Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
obtĭcesco (opt-), tĭcŭi, 3, v. inch. n. [obticeo], to become or be struck silent; in perf., to be silent (syn. obmutesco): obticuit obticescit, Not. Tir. p. 90: quid, amabo, opticuisti? Plaut. Bacch. 1, 1, 28: quid nunc obticuisti? Ter. Phorm. 5, 9, 2 (dub.; Umpfenb. and Fleck. obstipuisti): repente obticuit, Just. 32, 2, 3: nec prius obticuit quam, etc., Ov. M. 14, 523: chorus, Hor. A. P. 284; Mart. 10, 17, 4.
With acc.: cetera obticuit, Lact. Ira Dei, 4, 13.