onerous

Adjective

WordNet 3.0

Adjective (1)

not easily borne; wearing“the burdensome task of preparing the income tax return”“my duties weren't onerous; I only had to greet the guests”“a taxing schedule”Synonyms: burdensome taxing

Webster's Dictionary (GCIDE)

Onerous \On"er*ous\, a. [L. onerosus, fr. onus, oneris, a load, burden: cf. F. on['e]reux.] Burdensome; oppressive. "Too onerous a solicitude." --I. Taylor. [1913 Webster]

Onerous cause (Scots Law), a good and legal consideration; -- opposed to gratuitous. [1913 Webster]