a.
1.
Single, individual.
2.
Single, uncompounded, not complex.
3.
Unusual, uncommon, rare, unwonted, strange, extraordinary, remarkable, peculiar.
4.
Particular, peculiar, exceptional, unexampled, unparalleled, remarkable, unprecedented, unaccountable, strange.
5.
Remarkable, eminent, unusual, rare, extraordinary, exceptional.
6.
Unique.
7.
Peculiar, odd, eccentric, queer, fantastic, bizarre .