Lewis Short
hĕbĕtesco, ĕre
* V. inch. n. [hebes], to grow dull, dim, or faint (post-Aug. and very rare): aciem in cultris tonsorum,Plin. 28, 7, 23, § 79: acies oculi hebetescit ac paene caligat,Cels. 6, 6, 37: dolor hebetescit,Scrib. Comp. 56.
Charlton T. Lewis, Charles Short, A Latin Dictionary