in-serpo

psi, ptum, 3, v. n.
I. to crcep on or over any thing; only trop.; constr. with dat. (poet. and post-class.): jam somnus avaris Inserpit curis, Stat. Th. 1, 340: ei lanugo malis inserpebat, App. M. 7, p. 189 fin.
Lewis & Short
A Latin Dictionary, 1879
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