sēmis, issis (in Vitr., Front., and Pall. indecl., e.g. duo semis pedes, Pall. Febr. 9, 10: 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 10 s. 6 3/4 d. 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.