Definition of "long" in English

adjective

Having much distance in space from one end to the other.
- I need a long piece of wood.
- It’s a long way from the Earth to the Moon.
- How long was your newborn baby?
Travelling or extending too great a distance in space.
Having great duration.
- His speech was long and dull.
- The pyramids of Egypt have been around for a long time.
- I took a long look at the house, knowing it was for the last time.
Seeming to last a lot of time, due to being boring, tedious, tiring, irksome, etc.
- It took us three long weeks to clear the stones from the field.
- It'll be a long journey home for the travelling supporters after that 5-0 defeat.
(UK, Ireland, dated) Not short; tall.
(finance) Possessing or owning stocks, bonds, commodities, or other financial instruments with the aim of benefiting from an expected rise in their value.
- I’m long in DuPont.
- I have a long position in DuPont.
(cricket) Of a fielding position, close to the boundary (or closer to the boundary than the equivalent short position).
(gambling) Of betting odds, offering a very large return for a small wager.
Occurring or coming after an extended interval; distant in time; far away.
(African-American Vernacular, MLE, slang, of money) In great supply; abundant.
(slang, MLE) Clipping of taking a long time.
(slang, MLE, by extension) stupid; annoying; bullshit
(slang, MLE, by extension) serious; deadly.
(Canada, US, of paper or document layouts) Measuring 8½ in × 13 in.
(Philippines, of paper or document layouts) Measuring 8½ in × 14 in.

noun

(linguistics) A long vowel.
(prosody) A long syllable.
(music) A note formerly used in music, one half the length of a large, twice that of a breve.
(programming) A long integer variable, twice the size of an int, two or four times the size of a short, and half of a long long.
- A long is typically 64 bits in a 32-bit environment.
(finance) An entity with a long position in an asset; for example, a trader or investor possessing an amount of a company's shares.
- Every uptick made the longs cheer.

adverb

(chiefly sports) Over a great distance in space.
- Every golfer wants to hit the ball long and straight.
For a particular duration (specified by additional qualifying words accompanying it).
- How long is it until the next bus arrives?
- She has known us as long as you.
- I’ve waited long enough.
- He slept all day long.
- The meeting has already gone on much too long.
(placed before a verb, participle, adjective, preposition, or adverb) For a long time.
- Paris has long been considered one of the most cultured cities in the world.
- By eight o’clock, the food will be long gone.
- I seldom stay long after class, but yesterday I spent the evening and long into the night.
(placed by itself after a positive verb, rare) For a long time.
A long time (see usage notes).
- Will this interview take long?
- I haven’t got long to live.
- They are in a hurry; they can’t wait for too long.