verb (used with object) Informal.
Origin of psych1
Origin of psych-out
verb (mainly tr, adverb) informal
Word Origin for psych
as a noun, short for psychology in various senses (e.g. as an academic study, in student slang by 1895). As a verb, first attested 1917 as "to subject to psychoanalysis," short for psychoanalyze. From 1934 as "to outsmart" (also psych out); from 1963 as "to unnerve." However to psych (oneself) up is from 1972; to be psyched up is attested from 1968.
Analyze or understand something; also, anticipate the intentions of someone, as in It's hard to psych out the opposition's thinking, but we have to try.
Undermine the confidence of, intimidate. For example, The basketball team managed to psych out their opponents' guards. This expression is often used in the passive and can mean “lose one's nerve,” as in After I learned that he had two doctorates in the field, I was completely psyched out. Both slangy usages date from the second half of the 1900s and allude to influencing someone psychologically.