(a.) Seldom happening or occurring; rare; uncommon; as, the infrequent appearance of a comet\.

almost unheard-of cheeseparing chinchy chintzy exiguous meager miserly piddling poor rare scant scanty scarce scattered scrimping scrimpy seldom met with seldom seen skimping skimpy slim slow sparse spotty sprinkled stingy thin tight uncommon unfrequent unique unusual