Synonyms for Trying:

adj.

difficult (adjective)
difficult, adverse, uphill, fussy, wearisome, hard, oppressive, harsh, rugged, tight, strenuous, laborious, complex, complicated, rough, ticklish, formidable, thorny, arduous, wearying, burdensome, tough, severe, cantankerous, stressful, knotty, grinding, cumbersome, demanding, tricky, onerous, contrary, troublesome, bothersome, wearing, toilsome, finicky.
difficult, bothersome (adjective)
annoying, oppressive, taxing, irritating, Irksome, hard, aggravating, weighty, troublesome, exigent, stressful, wearisome, severe, onerous, exacting, tricky, rough, tight, arduous, strenuous, demanding, tough.
effortful (adjective)
effortful.
nerve-racking (adjective)
stressful.
painful (adjective)
stinging, cruel, woeful, aching, cutting, throbbing, annoying, uncomfortable, Besetting, anguishing, agonizing, crushing, acute, offensive, miserable, oppressive, harrowing, unpleasant, piercing, burdensome, disagreeable, stabbing, odious, unbearable, arduous, grievous, bothersome, Gnawing, hurtful, excruciating, sore, Irksome, irritating, wrenching, withering, aggravating, grueling, smarting, horrendous, painful, inflaming, Torturing., chafing, tormenting, distressful, biting, Cramping, troublesome, severe, bitter, insufferable.
vexatious (adjective)
irritating.
weary (adjective)
faint, drowsy, blue, droopy, feeble, fatigued, run down, footsore, Frazzled, tired, limp, flaccid, exhausted, debilitated, toilsome, listless, sleepy, apathetic, depressed, uphill, weak, Wayworn, cheerless, over-weary, wasted, weary, bored, worn-out.

n.

soporific, hypnotic. weighty, effortful, exacting, heavy, taxing, rigorous, exigent, backbreaking. troublesome (noun)
tiring.
trying (noun)
nerve-wracking, hard, stressful, difficult, nerve-racking, disagreeable.

v.

experimenting (verb)
investigating, probing, Proving, testing, Analyzing, Benchmarking, Assaying, researching, Checking, experimenting, determining, verifying.
punishing (verb)
Chastising, Castigating, judging, Disciplining, avenging, reprising, Crucifying, Imprisoning, Burdening, distressing, Correcting, Fining, penalizing, Afflicting, Sentencing, Persecuting, chastening, lambasting, Keelhauling, confining, punishing, Incarcerating, Pillorying, executing.

Other synonyms:

tiring, effortful, backbreaking. soporific, hypnotic. weighty, rigorous, exigent. taxing, exacting. heavy. Other relevant words:
effortful, hypnotic, nerve-wracking, taxing, rigorous, nerve-racking, heavy, soporific, exacting, weighty, exigent, backbreaking, tiring.

Usage examples for trying

  1. I have been trying to think." – Hills of the Shatemuc by Susan Warner
  2. " I'm trying to," I said. – Jack of No Trades by Charles Cottrell
  3. I was trying to remember all night. – Madge Morton, Captain of the Merry Maid by Amy D. V. Chalmers