seldomness

CIDE DICTIONARY

seldomness, n. 

 Rareness.  Hooker.  [1913 Webster]

ROGET THESAURUS

seldomness

Infrequency

N infrequency, rareness, rarity, fewness, seldomness, uncommonness, unfrequent, infrequent, rare, rare as a blue diamond, few, scarce, almost unheard of, unprecedented, which has not occurred within the memory of the ol, not within one's previous experience, not since Adam, scarce as hen's teeth, one in a million, few and far between, seldom, rarely, scarcely, hardly, not often, not much, infrequently, unfrequently, unoften, scarcely, scarcely ever, hardly ever, once in a blue moon, once, once in a blue moon, once in a million years, once for all, once in a way, pro hac vice, ein mal kein mal.