high (adj.)

Old English heh (Anglian), heah (West Saxon) "of great height, tall, conspicuously elevated; lofty, exalted, high-class," from Proto-Germanic *hauha- (source also of Old Saxon hoh, Old Norse har, Danish høi, Swedish hög, Old Frisian hach, Dutch hoog, Old High German hoh, German hoch, Gothic hauhs "high;" also German Hügel "hill," Old Norse haugr "mound"). The group is of uncertain origin; perhaps related to Lithuanian kaukara "hill," from PIE *kouko-. Spelling with -gh represents a final guttural sound in the original word, lost since 14c.

Of sound pitch, late 14c. Of roads, "most frequented or important," c. 1200 (high road in the figurative sense is from 1793). Meaning "euphoric or exhilarated from alcohol" is first attested 1620s, of drugs, 1932. Sense of "proud, haughty, arrogant, supercilious" (c. 1200) is reflected in high-handed and high horse. Of an evil or a punishment, "grave, serious, severe" (as in high treason), c. 1200 (Old English had heahsynn "deadly sin, crime").

High school "school for advanced studies" attested from late 15c. in Scotland; by 1824 in U.S. High time "fully time, the fullness of time," is from late 14c. High noon (when the sun is at the meridian) is from early 14c.; the sense is "full, total, complete." High finance (1884) is that concerned with large sums. High tea (1831) is one at which hot meats are served. High-water mark is what is left by a flood or highest tide (1550s); figurative use by 1814.

High and mighty is c. 1200 (heh i mahhte) "exalted and powerful," formerly a compliment to princes, etc. High and dry of beached things (especially ships) is from 1783.

high (n.1)

early 14c., "high point, top," from high (adj.). As "area of high barometric pressure," from 1878. As "highest recorded temperature" from 1926. Meaning "state of euphoria" is from 1953.

high (n.2)

"thought, understanding," Old English hyge, cognate with Old Saxon hugi, Old High German hugi, Old Norse hygr, Swedish hög, Danish hu. Obsolete from 13c. in English and also lost in Modern German, but formerly an important Germanic word.

high (adv.)

Old English heah; see high (adj.).

Definitions of high
high (n.)
a lofty level or position or degree;
summer temperatures reached an all-time high
high (n.)
an air mass of higher than normal pressure;
the east coast benefits from a Bermuda high
high (n.)
a state of sustained elation;
I'm on a permanent high these days
high (n.)
a state of altered consciousness induced by alcohol or narcotics;
they took drugs to get a high on
high (n.)
a high place;
they stood on high and observed the countryside
Synonyms: heights
high (n.)
a public secondary school usually including grades 9 through 12;
Synonyms: senior high school / senior high / highschool / high school
high (n.)
a forward gear with a gear ratio that gives the greatest vehicle velocity for a given engine speed;
Synonyms: high gear
high (adj.)
greater than normal in degree or intensity or amount;
a high temperature
he has a high opinion of himself
a high price
the river is high
high risks
the high point of his career
has high hopes
high (adj.)
(literal meaning) being at or having a relatively great or specific elevation or upward extension (sometimes used in combinations like `knee-high');
a high forehead
a foot high
a high mountain
high buildings
a high incline
high ceilings
high (adj.)
standing above others in quality or position;
the high priest
people in high places
Synonyms: eminent
high (adj.)
used of sounds and voices; high in pitch or frequency;
Synonyms: high-pitched
high (adj.)
happy and excited and energetic;
Synonyms: in high spirits
high (adj.)
(used of the smell of meat) smelling spoiled or tainted;
Synonyms: gamey / gamy
high (adj.)
slightly and pleasantly intoxicated from alcohol or a drug (especially marijuana);
Synonyms: mellow
high (adv.)
at a great altitude;
he climbed high on the ladder
Synonyms: high up
high (adv.)
in or to a high position, amount, or degree;
prices have gone up far too high
high (adv.)
in a rich manner;
he lives high
Synonyms: richly / luxuriously
high (adv.)
far up toward the source;
he lives high up the river