Definition of "POS"
POS
noun
countable and uncountable, plural POSes
(law) Initialism of proof of service.
(medicine) Initialism of peripheral oxygen saturation.
(linguistics) Initialism of part of speech.
(computing) Initialism of proprietary operating system.
(navigation, aviation) Initialism of position and orientation system.
(vulgar, of a person or thing) Initialism of piece of shit.