UNDESIRABLE
undesirable, unwanted
(adjective) not wanted; “undesirable impurities in steel”; “legislation excluding undesirable aliens”; “removed the unwanted vegetation”
undesirable, unsuitable
(adjective) not worthy of being chosen (especially as a spouse)
undesirable
(noun) one whose presence is undesirable; “rounding up vagrants and drunks and other undesirables”
Source: WordNet® 3.1
Etymology
Adjective
undesirable (comparative more undesirable, superlative most undesirable)
objectionable or not likely to please
Usage notes
• Nouns to which "undesirable" is often applied: effect, consequence, result, element, change, person, substance, characteristic, quality, feature, behavior, activity, thing, event, reaction, state.
Antonyms
• desirable
Noun
undesirable (plural undesirables)
an undesirable person
Source: Wiktionary