Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prō-cŭbo, āre, 1, v. n., to lie stretched out, to lie along (poet.): ubi saxea procubet umbra, Verg. G. 3, 145: procubat horrendus Getico Gradivus in Haemo, Claud. Consol. Prob. et Olyb. 119.