Nomen collectivum

NOMEN COLLECTIVUM. This expression is used to signify that a word in the singular number is to be understood in the plural in certain cases.
     2. Misdemeanor, for example, is a word of this kind, and when in the singular, may be taken as nomen collectivum, and including several offences. 2 Barn. & Adolph. 75. Heir, in the singular, sometimes includes all the heirs.