ONEROUS

[ 'əʊn(ə)rəs , 'ɒn- ]

■ adjective involving a great deal of effort, trouble, or difficulty.

↘ Law involving heavy obligations.

Derivatives

~ly adverb

~ness noun

Origin

ME: from OFr. onereus , from L. onerosus , from onus , oner- 'burden'.