Synonyms of unfrequent

1 Syllable
few, rare, odd
2 Syllables
random, special, scarce, fewest, casual, fewer, seldom, standout, rarest
3 Syllables
subtilest, sporadic, infrequent, rarer, subtiler, specific, unusual, especial, uncommon
4 Syllables
occasional, incidental, desultory, exceptional, exclusive, intermittent, particular