Meaning of invoke

(verb) summon into action or bring into existence, often as if by magic; "raise the specter of unemployment"; "he conjured wild birds in the air"; "call down the spirits from the mountain"

cite as an authority; resort to; "He invoked the law that would save him"; "I appealed to the law of 1900"; "She invoked an ancient law"

request earnestly (something from somebody); ask for aid or protection; "appeal to somebody for help"; "Invoke God in times of trouble"