Originally a Roman name consisted of three elements: a personal name (praenomen), and name indicating the clan (gens, pl. gentes) to which he belonged, and his filiation, that is, the indication of his father's praenomen. This system is unique to the peoples of ancient Italy (there is some variation in the filiation, which appears between the praenomen and nomen in some areas). Where and when this system arose is unknown.
最初，罗马人的名字是由三个部分组成的：①本名(praenomen＝given name)；②氏族名(gens, pl. gentes)，即表示该男子所从属的氏族的名字；③父名(filiation)，显示其父亲的本名。在远古的意大利人中这是很独特的（父名存在着某种变化，在某些地区，父名出现在本名和氏族名之间）。这一命名体系的起源时间及地域尚不得而知。
The praenomen was the personal name. The Romans had less than thirty of them in total and only about ten were at all common. They were normally abbreviated:
(In C. and Cn., the use of the letter C to represent the sound G shows an archaic use of the letter's original pronunciation.)
Certain praenomens were maintained only among particular patrician families: App.=Appius, Ser.=Servius. The names of the kings (apart from Romulus) all have the appearance of a regular Roman name, but their praenomens are often not among the normal ones of the later period: Numa, Tullus, Ancus. The attested nomen Tullius seems to be derived from a praenomen Tullus just as the nomen Marcius is derived from the praenomen Marcus, which suggests that there had been a praenomen Tullus, even though no such praenomen is attested in historical period. This peculiarity of praenomens perhaps lends credibility at least to the names of the kings: if the names had been made up, more regular ones would have been chosen.
某些本名仅仅在特定的氏族贵族家族中保留使用，例如App.=阿皮乌斯， Ser.=塞尔维乌斯等。除罗慕路斯之外的早期国王们都有着一个常见的罗马名字，可他们的本名都不属晚期常见的名字：努玛、图路斯、安库斯。正如氏族名Marcius源自本名Marcus一样，氏族名图利乌斯(Tullius)源自本名Tullus, 这似乎暗示有这么一个本名Tullus，虽然在历史上并没有记录有叫这个本名的人。这种奇怪的现象可能使得诸国王的本名更为可信：如果这些名字是臆造的，那也应该选一些更常见的名字。
The second element, the nomen, was in origin the name of a man's gens or clan. Everyone of freeborn origin supposedly originally went back to some common ancestor, though foreigners made citizens and freed slaves adopted regular Roman names. Native Roman nomens regularly end in -ius: (Julius, Tullius, Sempronius, Quinctilius), though by the late Republic one encounters other endings (esp. those of Etruscan origin).
第二个部分，氏族名源自该男子所属的(父系)氏族或家族。尽管归化为罗马公民的异邦人或是获释奴也会采用一个常见的罗马名字，凡是生而自由的人们都认为可被追溯到某个共同的祖先。罗马原有的氏族名一般会以”-ius”结尾：Julius, Tullius, Sempronius, Quinctilius(优利乌斯、图利乌斯、显普洛尼乌斯、昆克提利乌斯)，但到共和晚期时人们会遇到以其它音结尾的名字(特别是那些源自伊特鲁斯坎的名字)。
In the beginning the praenomen and nomen constituted a Roman's full name and were followed by the so-called filiation (a patronymic or indication of paternity). The filiation consisted of the Latin word for "son" filius (abbreviated by the latter f.) preceeded by the abbreviation of the father's praenomen, which was understood in the genitive. Hence, a Roman might have been known as M. Antonius M. f. (=Marci filius), that is, Marcus Antonius, the son of Marcus.
最初，罗马人的全名就是由本名和氏族名构成的，后面再加上所谓的父名(根据父亲的名字或是表示父子关系的名字)。父名中含有一个拉丁词filius（意为“之子”），缩写为“f.”，跟在按属格书写的父亲本名缩写之后。因此，我们所知的罗马人的名字可能是M. Antonius M. f. (=Marci filius)，意即：玛尔库斯·安托尼乌斯，玛尔库斯之子。
4) Tribal designation
By the Middle Republic the abbreviation for tribe in which the man was enrolled was added after his filiation. When this became an official part of the name is not known. By the 242 the number of tribes was fixed at 35. A tribe was not an indication of common ancestry; the tribes were distributed geographically and a man belonged to the tribe in which his main residence was located. The tribe was an essential part of citizenship, since voting was often carried out by tribe.
As can be imagined, this system could be rather confusing, given the small number of praenomens and nomens. Hence, men acquired nicknames to distinguish themselves from other men of the same name. These nicknames eventually became inherited by a man's sons and thus became the mark of individual families. As such, they constituted the third element of a Roman's name, the cognomen. Their secondary origin as nicknames is shown both by their position following the filiation and by the fact that some families never acquired them during the Republic, such as that of L. Opimius or that of M. Antonius. As nicknames, the cognomina tended to refer to physical or mental characteristics: Catus, Cato and Catullus all derive from catus meaning clever; Crispus (curly), Longus (tall) and Niger (black, i.e., dark-complexioned or dark-haired).
The origin of cognomens as nicknames is reflected in the fact that they do not appear in official documents until around 100 BC. The fact that cognomens are regularly used in the Fasti for the consuls of the earliest period of the Republic is evidence that the Fasti were in some form revised at a late date.
正如我们能想象到的，这种命名系统由于提供的本名数和氏族名数很少容易让人产生混淆。因此人们起了绰号来将自己和同名的其他人区分开来。这种绰号最后被其子辈继承成为区分不同家族的标志。如此，就构成了罗马人名字的第三部分，家族名。家族名作为绰号后起的另一个证明是他们的位置排在父名之后，还有一个事实就是某些家族在共和期间始终没有得到家族名，例如：L. Opimius或是M. Antonius。家族名作绰号时多指某些身体上或心理上的特征：卡图斯、加图和卡图路斯(Catus, Cato, Catullus)都源自拉丁语catus，意指聪明的。克利斯普斯(Crispus)源于curly,卷毛的, 隆古斯(Longus)源于高个子,尼格尔(Niger)源于黑色的(意指黑脸的或黑发的).家族名始于绰号还反映在下列事实上：直到BC100左右家族名都不曾在官方文件上出现过。共和国初年的执政官年表中使用了家族名,这一事实说明年表在晚近时代被人修改过。
Among the nobility, a distinction could even be made in families, a second cognomen being added which his descendants would bear, thus establishing a sub-family within a family. Such a second cognomen is called an agnomen. An example of this is Cornelii Scipiones Nasicae, who distinguished from the Cornelii Scipiones Africani. The Africani represent a very particular kind of agnomen. The name who conquered a foreign people was given an honorific agnomen derived from the name or location of that people, and his ancestors would inherit the agnomen. Being a member of the Cornelii Scipiones, P. Cornelius Scipio acquired the agnomen Africanus for having defeated the Carthaginians in the Second Punic War.
Under the Republic, because most nomina were fairly common, the higher aristocracy tended to dispense with their nomen, using their distinctive cognomen in its place. Hence, for instance, C. Caesar without Iulius.
There is inscriptional evidence to show that in the earliest period there were female versions of the praenomens and that women's names presumably consisted of a praenomen and nomen followed by filiation. By the time of the historically attested Republic, women no longer normally had praenomens. Instead, they were officially known only by the female form of their father's nomen. If further description was needed, the name was followed by the genitive of her father's name or, after marriage, of her husband. Hence, Cicero speaks of a woman as Annia P. Anni senatoris filia ("Annia the daughter of P. Annius the senator"). If only two daughters survived they could be distinguished as maior and minor ("the elder" and "the younger"). Mark Antony's daughters were known as Antonia maior (grandmother of the emperor Nero) and Antonia minor (mother of the emperor Claudius). More than two daughters were distinguished by ordinal numbers: Cornelia Quinta, the fifth daughter of a Cornelius. By the late Republic women also adopted the female form of their father's cognomen (e.g., Caecilia Metella Crassi, daughter of Q. Caecilius Metellus and wife of P. Licinius Crassus). This feminized cognomen was often made a diminutive (e.g., Augustus's wife Livia Drusilla was the daughter of a M. Livius Drusus).
有铭文证明，在最初的时代，有阴性化的本名，据推测，妇女的名字也是由本名，氏族名及后跟的父名组成。在史有明载的共和时代，，一般而言，妇人都不再有本名了。取而代之的，她们一般以阴性化的父亲的氏族名为人所知。假如尚需进一步的表述，后面再跟上其父名的属格形式，或，婚后是丈夫名字的属格形式。因此西塞罗称某位妇人为Annia P. Anni senatoris filia，意为“阿妮娅，元老普布利乌斯·阿尼乌斯之女”。假如只有两个女儿活下来了，则可以“大”(maior)和“小”(minor)来区分之。马克·安东尼的两个女儿就是以大安东尼娅(Antonia maior,尼禄皇帝之祖母)和小安东尼娅(Antonia minor,神圣的克劳狄乌斯皇帝之母)而为人所知的。如果有两个以上的女儿则以序数词区分之，例如，科尔涅利娅·昆塔，某个科尔涅利乌斯的第五个女儿(Cornelia Quinta, the fifth daughter of a Cornelius)。到共和末年，妇人也可继承其父亲的家族名，不过是阴性形式的(例如，凯奇丽娅·梅特拉·克拉希，克温图斯·凯奇利乌斯·梅特路斯之女，普布利乌斯·李锡尼乌斯·克拉苏之妻-Caecilia Metella Crassi, daughter of Q. Caecilius Metellus and wife of P. Licinius Crassus)。这种阴性化的家族名一般是加词尾变成小词(例如，奥古斯都的妻子利维娅·德路希拉就是某位玛尔库斯·李维乌斯·德路苏斯之女－Augustus's wife Livia Drusilla was the daughter of a M.Livius Drusus)。