ONEROUS
burdensome, onerous, taxing
(adjective) 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”
Source: WordNet® 3.1
Etymology
Adjective
onerous (comparative more onerous, superlative most onerous)
imposing or constituting a physical, mental, or figurative load which can be borne only with effort; burdensome.
Synonyms
• (burdensome): demanding, difficult, taxing, wearing
Source: Wiktionary
On"er*ous, a. Etym: [L. onerosus, fr. onus, oneris, a load, burden:
cf.F. onéreux.]
Definition: Burdensome; oppressive. "Too onerous a solicitude." I. Taylor.
Onerous cause (Scots Law), a good and legal consideration; -- opposed
to gratuitous.
Source: Webster’s Unabridged Dictionary 1913 Edition