allaboro

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.