pain, anguish or suffering resulting from mental or physical hardship.
3.
the pain of childbirth.
–verb (used without object)
4.
to suffer the pangs of childbirth; be in labor.
5.
to toil or exert oneself.
Origin: 1200–50; (v.) ME travaillen < OF travaillier to torment < VL *trepaliāre to torture, deriv. of LL trepālium torture chamber, lit., instrument of torture made with three stakes (see tri-, pale2); (n.) ME < OF: suffering, deriv. of travailler
Work, especially when arduous or involving painful effort; toil. See Synonyms at work.
Tribulation or agony; anguish.
The labor of childbirth.
intr.v.
tra·vailed, tra·vail·ing, tra·vails
To work strenuously; toil.
To be in the labor of childbirth.
[Middle English, from Old French, from travailler, to work hard, from Vulgar Latin *tripāliāre, to torture with a tripalium, from Late Latin tripālium, instrument of torture, probably from Latin tripālis, having three stakes : tri-, tri- + pālus, stake; see pag- in Indo-European roots.]
[truh-veyl, trav-eyl] 
eɪl