labor, labour, toil, fag, travail, grind, drudge, dig, moil -- (work hard; "She was digging away at her math homework"; "Lexicographers drudge all day long")
tug, labor, labour, push, drive -- (strive and make an effort to reach a goal; "She tugged for years to make a decent living"; "We have to push a little to make the deadline!"; "She is driving away at her doctoral thesis")
labor, labour -- (undergo the efforts of childbirth)
Overview of adj labouring
The adj labouring has 1 sense
drudging, laboring, labouring, toiling -- (doing arduous or unpleasant work; "drudging peasants"; "the bent backs of laboring slaves picking cotton"; "toiling coal miners in the black deeps")