Meaning of first-in, first-out

first-in first-out

Pronunciation: (fûrst'in', fûrst'out'), [key]
  1. an inventory plan that assumes that items purchased first will be sold first and that by valuing inventory items at the price of the most recent purchases, inventory values will be comparable to any rise in prices. Abbr.: FIFO  Cf.
  2. See(def. 2).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.