adj

• Having much distance in space from one end to the other.
  "My ex was very strong but not very long."
• Travelling or extending too great a distance in space.
  "The plane touched down long and overran the end of the runway."
• Travelling or extending too great a distance in space.
  "That forehand was long. It landed two feet beyond the baseline."
• (UK, Ireland, dated) Not short; tall.
  "The colonel and his sponsor made a queer contrast: Greystone [the sponsor] long and stringy, with a face that seemed as if a cold wind was eternally playing on it."

noun

• (linguistics) A long vowel.
  "In French most vowels are half-long, and are only occasionally lengthened or shortened into full longs and shorts."
• (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."

verb

• (transitive, finance) To take a long position in.
  "The left panel shows the profile of a portfolio consisting of longing a call and shorting a put."

adv

• (chiefly sports) Over a great distance in space.
  "Every golfer wants to hit the ball long and straight."
• (chiefly sports) Over a great distance in space.
  "She hit her return long and lost the point."
• (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."
• (placed by itself after a positive verb, rare) For a long time.
  "It’s an earth song,— And I’ve been waiting long for an earth song. It’s a spring song,— And I’ve been waiting long for a spring song.[…] I have been waiting long for this spring song."