Lewis Short
(Adj.adj.) : simplus, a, um.
* Adj.kindr. with simplex, simple; as adj. only post-class.: mors, Prud. στεφ. 10, 878.—More freq.
* Substt.
* Simplum, i, n., that which is single or simple, the simple sum or number (opp. to the double): duplum simplum,Cic. Top. 11, 49: simplum solvere,Plaut. Poen. 5, 6, 25 (opp. duplum, id. ib. 5, 6, 14): si simplum imperetur,Liv. 29, 15; Dig. 49, 14, 5.
* Simpla, ae, f. (sc. pecunia), the simple purchase-money, Varr. R. R. 2, 10, 5; Dig. 21, 2, 60.
Charlton T. Lewis, Charles Short, A Latin Dictionary