Synonyms for Under:

adj.

all (adjective)
nether.
inferior (adjective)
dependent, subject, subservient, second, lesser, inferior, junior, below, subordinate, underling.
less (adjective)
lower than, below, beneath, less.
lower (adjective)
lower.
subordinate (adjective)
constrained, subordinate, bound, subjugated, dependent, obedient, supine, servile, enslaved, subject, submissive, subservient, junior, unfranchised, Subjected, compliant, deferent, enthralled.

adv

under (adverb)
underneath, lower than, below, beneath.

adv.

below (adverb)
underneath, inferior, supporting, nether, beneath, down, lower, downward.
secondary (adverb)
following, subject, subordinate, obedient, low, junior, lesser, dependent, subjugated, subservient.
under (adverb)
underneath.

n.

strictly speaking, in the eyes of the law/world etc., depending on, following, different, by, in accordance with, on (someone's/something's) merit, apart, on a case-by-case basis, according to. big, insufficient, after, excess, Of, naming ceremony, nameless, wanting, scarce, short, nee, assignment, namesake, inadequate, initial, deficient, shy. peer, age, secondary, old, minor, subaltern, petty, small, minor league, at, age bracket, lower, contemporary, age gap, aged, smalltime. comatose, out, out for the count, sound asleep, out cold, unconscious, fast asleep, asleep, semiconscious. subterranean, underfoot, underwater, underlying, underground. encrusted, thinly, crusted, Caked, thickly, clothed, be tipped with something. astrology (noun)
aries, capricorn, chart, cancer, astrology, astrologer, astrological, aquarius, cast, gemini.
inferior (noun)
nether.
under (noun)
below, low, subordinate, nether, low-level.

prep.

inferior (preposition)
beneath.
lower (preposition)
below.

Other synonyms:

Caked, comatose, encrusted, age bracket, semiconscious, ascending, crusted, downward, underlying, aged, smalltime, subterranean, according to, age gap, skyward. thinly, scarce, down, secondary, minor league, bouncy, age, old, insufficient, subaltern, clothed, minor, inadequate, asleep. peer, shy, contemporary, deficient. unconscious, thickly, lower. petty, small, at, by. wanting. short. out. beneath
underfoot.
submarine
underwater.
subterranean
underground.

Usage examples for under

  1. " She's gettin' under way, like enough. – Uncle William The Man Who Was Shif'less by Jennette Lee
  2. Under your bed, where they belong. – Gaslight Sonatas by Fannie Hurst