al-lăbōro (adl-), āvi, ātum, 1, v. a. (only twice in Hor.),
to labor or toil at a thing : ore adlaborandum est tibi, Hor. Epod. 8, 20.—And with dat., to add to with labor or pains : simplici myrto nihil adlabores, Hor. C. 1, 38, 5.
ad-labōrō (all-) —, —, āre, to labor, toil: ore adlaborandum est tibi, ut, etc., H. — With dat, to ...
An Elementary Latin Dictionary