1 odd, strange, different, peculiar, funny, curious, uncommon, unconventional, unorthodox, atypical, singular, exceptional, anomalous, extraordinary, unusual, weird, bizarre, uncanny, unnatural, freakish, remarkable, offbeat, irregular, unparalleled, incongruous, outlandish, outré, exotic, eccentric, fey, quaint, absurd, ridiculous, ludicrous, unexampled:
How do you explain Basil's queer behaviour at the office party? Her attire could only be described as queer, given her age and status
2 questionable, dubious, suspicious, suspect, doubtful, puzzling, mysterious, Colloq fishy, shady:
We had a feeling that something queer was going on when the clocks started running backwards
3 (slightly) ill, queasy, sick, unwell, poorly, faint, uneasy, dizzy, giddy, vertiginous, light-headed:
It's not surprising that you feel queer after drinking all that wine
4 mad, unbalanced, unhinged, demented, deranged, insane, daft, touched, Colloq dotty, potty, nutty, nuts, loony, batty, cracked:
Francis seems to have gone a bit queer - fancies himself a reincarnation of Cicero.
5 ruin, spoil, bungle, botch, muddle, muff, mar, wreck, destroy, Colloq make a hash or mess of, gum up (the works), Slang muck up, screw up, louse up, US ball up, Taboo Slang Brit balls up:
Grimstone queered the deal by telling the buyer the company was worth half what we were asking.