“the top of a high mountain”
synonyms: tall, lofty, towering, soaring, elevated, giant, big; More
antonyms: short

(after a measurement and in questions) measuring a specified distance from top to bottom.
“a tree forty feet high”

far above ground, sea level, or another point of reference.
“a palace high up on a hill”

extending above the normal level.
“a round face with a high forehead”

(of an area) inland and well above sea level.
“high prairies”

performed at, to, or from a considerable height.
“high diving”

(of latitude) close to 90°; near the North or South Pole.
“high southern latitudes”

“a high temperature”
synonyms: inflated, excessive, unreasonable, overpriced, sky-high, unduly expensive, dear, costly, top, exorbitant, extortionate, outrageous, prohibitive; More
antonyms: reasonable, light, calm

of large numerical or monetary value.
“they had been playing for high stakes”

very favourable.
“she had no very high opinion of men”
synonyms: favourable, good, positive, approving, admiring, complimentary, commendatory, appreciative, flattering, glowing, adulatory, approbatory, rapturous, full of praise; More
antonyms: unfavourable
extreme in religious or political views.
“a man of high Tory opinions”

(of a period or movement) at its peak.
“high summer”

1.a high point, level, or figure.
“commodity prices were at a rare high”
synonyms: high level, high point, record level, peak, record, high water mark; More
antonyms: low
a high-frequency sound or musical note.
“piercing highs and subterranean lows”
a high power setting.
“the vent blower was on high”
an area of high barometric pressure; an anticyclone.
2.a notably happy or successful moment.
“the highs and lows of life”
informal
a state of high spirits or euphoria.
“if the stable is doing well then everybody’s on a high”
synonyms: ecstatic, euphoric, delirious, elated, thrilled, overjoyed, beside oneself, walking on air, on cloud nine/seven, in seventh heaven, jumping for joy, in transports of delight, carried away, transported, rapturous, in raptures, exultant, jubilant, in a frenzy of delight; More
antonyms: depressed
3.NORTH AMERICANinformal
high school.
“I go to junior high”

1.at or to a considerable or specified height.
“the sculpture stood about five feet high”
synonyms: at great height, high up, far up, way up, at altitude; More
antonyms: low
2.highly.
“he ranked high among the pioneers of chemical technology”
at a high price.
“buying shares low and selling them high”
3.(of a sound) at or to a high pitch.
“my voice went high with excitement”