POO

POO (plural POOs)

1. (historical) Initialism of post-office order.
   • 1856 June 28, John Addington Symonds, letter in Letters, Vol. I, p. 75:

     Thank Papa very much for the P.O.O. which I got cashed without difficulty.

   • 1877, Army and Navy Gazette - Volume 18, page 192:

     A Coupon will be found below, which will be redeemed if accompanied by P.O.O. for 1s. 6d or 20 stamps.

   • 2013, R. L. Wallace, The Canary Book, →ISBN:

     ... it is customary after the bargain is made for the purchaser to send a P.O.O. for the amount before the birds are sent off.

• “P, 135752.”, in OED Online ⁠, Oxford: Oxford University Press, 2005.

• OOP, oop

POO f (uncountable)

1. Initialism of programmation orientée objet. (OOP)