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. last-in, first-out.
2. Computers.See FIFO (def. 2).
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.