in-sŏnus

a, um, adj.
I. without sound, noiseless, silent (post-class.).
I. Lit.: passus, Amm. 27, 12; cf. gressus, id. 29, 5: vestigium, App. M. 3, p. 138, 22.—
II. Transf.: litterae, i. e. mutae, App. de Mundo, p. 66, 29.
Lewis & Short
A Latin Dictionary, 1879
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