| Noun | 1. | undesirable - one whose presence is undesirable; "rounding up vagrants and drunks and other undesirables" |
| Adj. | 1. | undesirable - not desirable; "undesirable impurities in steel"; "legislation excluding undesirable aliens" Antonyms: desirable - worth having or seeking or achieving; "a desirable job"; "computer with many desirable features"; "a desirable outcome" |
| 2. | undesirable - not worthy of being chosen (especially as a spouse) Synonyms: unsuitable |