Such are: Āfricus, sc. ventus; Āfrica, sc. terra; calda, sc. aqua; cānī sc. capillī; circēnsēs, sc. lūdī; decuma, sc. pars; fera, sc. bēstia; hīberna, sc. castra; merum, sc. vīnum; nātālis, sc. diēs; patria, sc. terra; praetexta, sc. toga; summa, sc. rēs; trirēmis, sc. nāvis, and many others.
[1103.] Certain adjectives denoting relationship, friendship, hostility, connection, or age, may be used in both numbers as substantives.
Such are: (a.) adfīnis, cōgnātus, cōnsanguineus, gentīlis, necessārius, propīnquus; (b.) adversārius, amīcus, inimīcus, familiāris, hostis, intimus, invidus, socius, sodālis; (c.) contubernālis, manipulāris, vīcīnus; (d.) adulēscēns, aequālis, iuvenis, senex.
[1104.] The masculine plural of many adjectives is used substantively to denote a class.
Such are: bonī, the good, the well-disposed, conservatives, patriots, our party; improbī, the wicked, the dangerous classes, revolutionists, anarchists, the opposite party; doctī, indoctī; piī, impiī, and the like.
[1105.] Proper names of men are used in the plural to denote different persons of the same name, or as appellatives to express character, oftenest good character: as,
duo Metellī, Celer et Nepōs, Br. 247, the two Metelluses, Celer and Nepos. quid Crassōs, quid Pompēiōs ēvertit? J. 10, 108, what overthrew a Crassus, Pompey what? i.e. men like Crassus and Pompey.
[1106.] The neuter plural of adjectives of all degrees of comparison is very often used as a substantive.
Such adjectives are usually in the nominative or accusative, and may have a pronoun, a numeral, or an adjective, agreeing with them. In English the singular is often preferred. Such are: bona, mala; vēra, falsa; haec, this; omnia, everything; haec omnia, all this, &c., &c.