adjective

1. measuring much from end to end in space or from beginning to end in time; not short or brief
2. measured from end to end rather than from side to side the long dimension
3. of a specified extent in length a foot long
4. of greater than usual or standard length, height, quantity, etc. a long game, a long window, a long ton
5. containing many items or members: said of a series, list, etc.
6. overextended in length
7. taking too much time; tedious; slow
8. extending to what is distant in space or time; far-reaching a long view of the matter
9. large; big the long odds of 100 to 1, to take a long chance
10. having an abundance of: with of or on long on excuses
11. ☆ Finance holding a commodity or security in anticipation of a rise in price
12. 1. Phonet. lasting for a relatively long time: said of a speech sound
    2. popularly diphthongized the long a in “pain”
13. Prosody
    1. requiring a relatively long time to pronounce: said of syllables in quantitative verse
    2. stressed: said of syllables in accentual verse

Etymology: ME < OE, akin to Ger lang < Gmc *lango- > ON langr, Goth laggs: ? akin to L longus

adverb

1. for a long time
2. for the duration of; from the beginning to the end all day long
3. at a much earlier or a much later time than the time indicated; remotely to stay long after midnight

noun

1. a variation of clothing size longer than the average for that size
2. long pants
3. a signal, syllable, etc. of long duration
4. a long time it won't take long to finish the work