Entry 3 senses · 2 variants Webster, 1913 Lacerta · La·cer·ta · IPA n. n. 01 n. A fathom. 1. A fathom.[Obs.] 02 n. A genus of lizards. See Lizard. 1. A genus of lizards. See Lizard.(Zool.) See: Lizard 2. The Lizard, a northern constellation.(Astron.)