happening or occurring at long intervals or rarely

infrequent visits.

not constant, habitual, or regular

an infrequent visitor.

not plentiful or many

infrequent opportunities for advancement.

far apart in space.

adjective

common , frequent , often , usual

adjective

exceptional , few , few and far between , isolated , limited , meager , occasional , odd , rare , scant , scanty , scarce , scattered , seldom , semioccasional , sparse , spasmodic , sporadic , stray , uncommon , unusual , intermittent , irregular