Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
allēgātus (adl-), ūs, m. [1. allēgo], an instigating to a deceit or fraud (cf. 1. allego, I. B.): meo adlegatu venit, Plaut. Trin. 5, 2, 18; cf. Gell. 13, 20, 19.