Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
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.