verb (used with object) Informal.
Origin of psych1
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.
Excite emotionally, as in The chorus was really psyched up for performing in Symphony Hall. [Slang; c. 1970]