noun:

• thorn; spine; prickle
• splinter (esp. lodged in one's flesh); hard sharp item (esp. lodged in one's throat, e.g. fish bone)
• biting words

adverb / ~と adverb:

• sticking; clinging - onomatopoeia
• with a smack (e.g. sitting down); hard - onomatopoeia
• all over; thickly - onomatopoeia

adverb / ~と adverb:

• (eating) heartily - onomatopoeia
• energetically; vigorously; (working) hard; enthusiastically - onomatopoeia

adverb / ~と adverb / ~する noun:

• bulging (muscles); welling up (of strength, courage, etc.) - onomatopoeia

adjective:

• painful; bitter; heart-breaking; difficult (emotionally)
• tough; difficult; hard (usu. of situations) ➜ 辛い【づらい】
• cruel; harsh; cold

adjective:

• seductive; carnal; enchanting
• troubling; difficult; thorny; hard
• anxious; uneasy

ichidan verb / transitive:

• to nail
• to knock; to bang (e.g. one's head); to strike (hard) ➜ 打付ける【ぶつける】
• to throw (e.g. a rock); to fling ➜ 打付ける【ぶつける】

~と adverb / adverb:

• ticktock - onomatopoeia
• chinking (e.g. of a hammer against rock); knocking; clicking; clacking; clattering - onomatopoeia

~の noun / adjectival noun:

• dry and hard; (frozen) stiff - onomatopoeia
• hidebound; die-hard; stubborn; obstinate; bigoted - onomatopoeia
• scared stiff; tense; nervous; frightened - onomatopoeia

godan ~る verb / intransitive verb:

• to be packed (with); to be full (space, schedule, etc.)
• to be blocked (road, pipe, etc.); to be clogged; to be plugged up ➜ 鼻が詰まる
• to shorten (width, interval, etc.); to shrink (shirt, word form, etc.); to narrow
• to be at a loss; to be hard pressed - often in the form …につまる ➜ 言葉に詰まる・気の詰まる【きのつまる】
• to end up; to be settled ➜ 詰まる所【つまるところ】
• to become a geminate consonant ➜ 促音【そくおん】
• to hit the ball near the handle of the bat - Baseball term

noun:

• coin
• hard currency ➜ 軟貨

noun:

• serious wound
• hard blow

adverb / ~と adverb:

• creaking; squeaking - onomatopoeia

adverb / ~と adverb / adjectival noun:

• packing in tightly; cramming; squeezing - onomatopoeia

adverb / ~と adverb:

• hard (pressing, tying, twisting, etc.); tightly; with force - onomatopoeia

adverb / adjectival noun / ~の noun:

• going hard (on someone); tormenting (e.g. with questions) - onomatopoeia

noun / ~する noun:

• roar of laughter (from several people)
• laughing hard (single person) - colloquialism

adjectival noun / adverb / noun:

• tearing; ripping; scratching - onomatopoeia
• crunching; munching - onomatopoeia
• stiff; starchy; crisp - onomatopoeia
• (working) hard; actively; vigorously; energetically - onomatopoeia
• making loud noises in succession (firing bullets, vehicle revving up, etc.) - onomatopoeia
• crackling (electricity) - onomatopoeia

expression / adjective:

• unable to compete with; not able to make a dent in (e.g. a problem); not able to get a solid hit in (e.g. in a fight)
• hard to chew

godan ~す verb:

• to use one thing for several purposes; to use the same thing on multiple occasions
• to work someone hard; to order around; to boss

noun / ~する noun / ~の noun:

• using all of one's strength (to); giving (it) everything one has got; going full-out - four character idiom
• throwing a ball as hard as one can - Baseball term

adverb:

• piercingly (as though cutting with a sharp sword) - onomatopoeia ➜ ぐさりと
• hard-hitting (e.g. criticism) - onomatopoeia

noun:

• worker ant
• hard worker - colloquialism

godan ~す verb / intransitive verb:

• to ram one's opponent head-first in the initial charge - Sumo term
• to punch hard; to hit hard

noun:

• worker bee
• hard worker - colloquialism

adverb / ~と adverb / ~する noun:

• scraping; scratching - onomatopoeia

~の noun / adjectival noun:

• hard (to the bite, to the touch) - onomatopoeia

adjectival noun:

• grave; solemn; serious
• harsh (e.g. truth); hard; strict

adverb / ~と adverb / ~する noun:

• tightly (holding on); firmly; securely - onomatopoeia
• strongly (built); solidly; sturdily; steadily - onomatopoeia
• properly; well; sufficiently; hard (working, etc.); fully; completely - onomatopoeia
• reliably; dependably; levelheadedly; shrewdly; wisely; cleverly - onomatopoeia

adverb / ~と adverb:

• acutely (feel); keenly; severely
• tightly; hard

adverb / ~と adverb / ~する noun:

• whirling; revolving; spinning; going round and round - onomatopoeia
• coiling around; winding around; rolling around - onomatopoeia
• working tirelessly; working hard - onomatopoeia
• constantly changing - onomatopoeia