adj. 25B6; adjective
a vexed expression : ANNOYED, irritated, cross, angry, infuriated, exasperated, irked, piqued, displeased, put out, disgruntled; informal aggravated, peeved, nettled, miffed, miffy, riled, hacked off, hot under the collar; Brit. informal narked, shirty; N. Amer. informal teed off, ticked off, sore, bent out of shape; archaic wroth.
the vexed issue of immigration : DISPUTED, in dispute, contested, in contention, contentious, debated, at issue, controversial, moot; problematic, difficult, knotty, thorny.