Synonyms for Seldom:

adj.

few (adjective)
few and far between.

adv.

hardly (adverb)
infrequently.
infrequently (adverb)
little, irregularly, scarcely, sporadically, rarely, a few times, on and off, whimsically, hardly ever, hardly, inhabitually, not often, once in a blue moon, unusually, sometimes, from time to time, uncommonly, scarcely ever, occasionally, not very often, once in a while, in a few cases, every now and then.
once in a while (adverb)
once in a while.

adv

every now and then (adverb)
occasionally.
hardly (adverb)
once in a blue moon, not often.
infrequently (adverb)
uncommonly, sporadically.
little (adverb)
hardly ever.

n.

few and far between, once or twice, rare, rarity. little, sporadically, infrequently, usual, once in a blue moon, occasionally. rarely (noun)
irregularly, when occasion permits, in a few cases, sporadically, hardly ever, sometimes, once in a blue moon, scarcely ever, from time to time, a few times, on and off, scarcely, occasionally, not often, uncommonly, once in a lifetime, at times, infrequently, when the spirit moves, once in a while, not in a month of Sundays, inhabitually, on divers occasions, every now and then, not very often, unusually, whimsically, hardly.
seldom (noun)
rarely.

Other synonyms:

once or twice, once in a while. sporadically, rarity. rare. little. at times
sometimes.
from time to time
every now and then.
now and then
on and off.
rarely
uncommonly, rarely.
scarcely
hardly.
seldom
infrequently.
Other relevant words:
occasionally, scarcely, rarely, rare, inhabitually, unusually, whimsically, hardly ever, little, hardly, once in a while, every now and then, scarcely ever, once in a blue moon, in a few cases, a few times, sometimes, irregularly, uncommonly, infrequently, on and off, from time to time, rarity, not very often, not often, sporadically.

Usage examples for seldom

  1. It is seldom that we want any great thing from our friends. – The Claverings by Anthony Trollope
  2. But sometimes, when I do think about it at all,- which I do as seldom as I can,- it seems to me that I might still become a different fellow if it were possible for me to marry her." – Can You Forgive Her? by Anthony Trollope
  3. Or rather, suppose them man and wife, because one seldom sees them together. – The Ontario Readers: The High School Reader, 1886 by Ministry of Education