Synonyms for Harsh:

adj.

all (adjective)
rough.
conflicting (adjective)
brawling, raucous, clashing, antipathetic, hostile, conflicting, clamoring, antagonistic, cacophonous, feuding, tense, colliding, dissenting, discordant, loath, bickering, warring, dissident, rowing, differing, Squabbling, rioting, contentious, dissonant, disharmonious.
critical (adjective)
carping, critical, Fault-finding, caviling, judgmental, derogatory, picky, finicky, disparaging, captious, pedantic.
depressing (adjective)
bleak.
difficult (adjective)
cantankerous, complex, contrary, wearisome, knotty, demanding, tough, wearing, adverse, fussy, ticklish, burdensome, tight, rugged, trying, strenuous, cumbersome, severe, finicky, laborious, formidable, thorny, wearying, stressful, rough, toilsome, uphill, difficult, tricky, grinding, hard, complicated, oppressive, arduous, onerous, bothersome, troublesome.
discordant (adjective)
Inconsonant, unmelodious.
discourteous (adjective)
uncivil, ungrateful, ungracious, rude.
nasty, abusive (adjective)
dour, stringent, brutal, relentless, unpleasant, gruff, ungracious, unkind, tough, uncivil, cruel, pitiless, austere, stern, rude.
rough (adjective)
cragged.
rough, crude (to the senses) (adjective)
cracked, craggy, dissonant, unmelodious, hoarse, unrelenting, screeching, uneven, astringent, grating, rigid, clashing, rugged, jarring, strident, noisy, disturbing, disagreeing, flat, incompatible, glaring, raucous, unmusical, rasping, jangling, rusty, tuneless, earsplitting, severe, grim, hard, discordant, Caterwauling, bleak, jagged, cacophonous, sharp.
severe (adjective)
basic, grim, firm, tart, dour, draconian, strait-laced, keen, lean, demanding, severe, imperial, oppressive, dry, puritanical, censorious, cutting, austere, fundamental, resolute, intolerant, unbending, stern, blunt, stringent, inflexible, strict, icy, intense, authoritarian, abrupt, meticulous, cool, curt, obstinate, chilly, rigid, spare, stark, obdurate, spartan, brisk, crisp, frosty, astringent, sharp, uncompromising, precise, caustic, hidebound, piquant, raw, correct, ascetic, stiff-necked, brusque, relentless, disciplined, rigorous, acute, unrelenting, critical, acerbic, prudish, acrimonious, exacting, short, gruff, bleak.
sharp (adjective)
sharp.
shrill (adjective)
raucous, jarring, screaming, piercing, rasping, strident, squeaky, hoarse, scratching, creaky, whistling, cutting, squealing, treble, reedy, jangling, whining, scraping, ear-piercing, screeching, shrieking, penetrating, Caterwauling, acute, shrill, grating, high-pitched.

n.

impermeable, porous, impure, impervious, solid, squawky, permeable, photosensitive, absorbent. hateful, uncharitable, taste, pitiless, evil, monstrous. brittle, tinny, hot, attitude, brassy, tuneless, monotonous. inclement, threatening, muggy, comfort, humid, unseasonable, sultry. harsh (noun)
brutal, cruel, hard, abrasive, unkind, disagreeable, rigorous, rough, unpleasant, heavy.
inharmonious (noun)
unsympathetic, rusty, clamorous, Inconsonant, unmelodious, earsplitting, uncomforting, disagreeing, cracked, unmusical, incompatible, disturbing, uncongenial, flat, loud, noisy.

Other synonyms:

objectionable, absorbent, impermeable, squawky, cragged, sultry, impure, solid, impervious, unseasonable, humid, Ironbound, photosensitive, muggy, unattractive, tuneless, permeable, porous. rude, craggy, loud, tinny, pitiless, scabrous, threatening, jagged. uneven, ragged. unyielding. brittle. awful. ruthless
inclement.
unharmonious
unmelodious.
Other relevant words:
cruel, rude, pitiless, brutal.

Usage examples for harsh

  1. His distressed voice was less harsh – There was a King in Egypt by Norma Lorimer
  2. In like manner, any adjective of quality, when its meaning is limited by the adverb too, so, as, or how, is put before the article; as, " Too great a study of strength, is found to betray writers into a harsh manner." – The Grammar of English Grammars by Goold Brown
  3. The harsh voice said as grimly as before: You come from the planet below us? – The Pirates of Ersatz by Murray Leinster