Definition of "ab"

ab¹

/æb/

noun
plural abs
1. (informal) abdominal muscle.
  Quotations
  The bikinied models in most of the ESPN2 shows have abs. Many of the malnourished bikinied models in the commercials have visible rib cages. How did the two get conflated into a shared vision of beauty?
  2006, H. Peter Steeves, The Things Themselves, page 75
  When possible, do your ab workout on a day when you're not training a major muscle group […] .
  2010, Bill Geiger, "6-pack Abs in 9 Weeks", Reps! 17:106

ab²

/æb/

noun
plural abs
1. (slang) An abscess caused by injecting an illegal drug, usually heroin.

ab³

/æb/

verb
third-person singular simple present abs, present participle abbing, simple past and past participle abbed
1. (climbing, informal) To abseil.
  Quotations
  I had a climbing rope in my pack, set up an abseil with it, and abbed down to him.
  1998, Climbing, numbers 178-180, page 22
2. Abbreviation of abort.
noun
1. Abbreviation of abortion.
preposition
1. Abbreviation of about.
adverb
1. Abbreviation of about.

ab⁴

/æb/

noun
plural abs
1. (US) The early stages of; the beginning process; the start.