I.“duobus semis pedibus,” id. Jan. 10, 3; 13, 7: “diametros octo semis,” Vitr. 4, 1: “passuum milium et semis,” Front. Aquaed. 7; cf.: “habere duos et semis cubitos,” Vulg. Exod. 25, 10 al.), m. cf. semi-; Gr. ἡμι-, ἥμισυ, a half, half-unity, a semi-unit (v. as, I.).
I. In gen. (very rare for the usual dimidium): “sex domini semissem Africae possidebant,” Plin. 18, 6, 7, § 35: “patrimonii,” Dig. 36, 1, 78, § 7: “e libertorum defunctorum bonis,” Suet. Ner. 32: “cum alter semissem, alter universa fratre excluso (sibi vindicaret),” Quint. 7, 1, 62: “panem semissem ponebat supra torum,” Petr. 64, 6.—
II. In partic. (freq. and class.).
A. As a coin,
1. Half an as, a semi-as, Varr. L. L. 5, § 171 Müll.; cf. Prisc. p. 708 P.; Plin. 33, 3, 13, § 44: “lex frumentaria de semissibus et trientibus,” Auct. Her. 1, 12, 21; Cic. Sest. 25, 55; Liv. Epit. 60; Ascon. ap. Cic. Pis. 4, p. 9 Orell.; hence, non semissis homo, not worth a groat, i. e. good for nothing, worthless, Vatin. ap. Cic. Fam. 5, 10 a, 1: “quid fit! Semis,” Hor. A. P. 330.—
2. In the times of the later emperors, as a gold coin, a half aureus (containing 59.8 grains of gold, or the present value of 10s. 6 3/4d. sterling), Lampr. Alex. Sev. 39.—
B. As a rate of interest, one half per cent. a month, or, acc. to our mode of computation, six per cent. a year (cf.: “bes, triens, etc.): semissibus magna copia (pecuniae) est,” Cic. Fam. 5, 6, 2: “usura multiplicata semissibus,” Plin. 14, 4, 6, § 56: “usura semissium,” Col. 3, 3, 9 sq.; “for which also, reversely: semisses usurarum,” id. 3, 3, 9; “and in apposition: semisses usuras promisit,” Dig. 22, 1, 13; 22, 45, 134; 46, 3, 102 fin.—
C. As a measure of dimension.
1. Half a juger of land: “bina jugera et semisses agri assignati,” Liv. 6, 16 fin.; cf. Col. 5, 1, 11; Plin. 18, 19, 49, § 178.—
2. A half-foot, half a foot: “interesse sesquipedes inter bina semina in latitudinem, in longitudinem semisses,” Plin. 17, 21, 35, § 160: “campestris locus alte duos pedes et semissem infodiendus est,” Col. 3, 13, 8; Vitr. 4, 1; Front. Aquaed. 7; Pall. Jan. 10, 2; 10, 4; 13, 7; id. Febr. 9, 10 et saep.; Veg. 5, 40, 3; 3, 11, 4.—
3. Half a cubit: “cubitum ac semissem,” Vulg. Exod. 25, 17.—
D. Among mathematicians, the number three, Vitr. 3, 1, 6; cf. as fin.
