Definition of psy-op in US English:

psy-op

noun

US
  • (A) In plural = "psychological warfare". (b) A noncombative military operation intended to influence the morale or attitude of one's opponent. Chiefly attributive.

Origin

1960s; earliest use found in The Christian Science Monitor. From psy- + op, after psy-war.

Pronunciation

psy-op

/ˈsʌɪˌɒp/