Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cernŭo, āvi, ātum, 1, v. a. and n. [cernuus], to throw or fall head foremost (only ante- and post-class.), Varr. ap. Non. p. 21, 8; App. M. 1, 19, p. 111, 9; Front. Princ. Hist. 5.
In dep. form: tigres cernuantur, Sol. 17: equus de industriā cernuatus, id. 45.