To call on (a higher power) for assistance, support, or inspiration: "Stretching out her hands she had the air of a Greek woman who invoked a deity\u201d ( Ford Madox Ford). To appeal to or cite in support or justification. To call for earnestly; solicit: invoked the help of a passing motorist. To summon with incantations; conjure. To resort to; use or apply: "Shamelessly, he invokes coincidence to achieve ironic effect\u201d ( Newsweek). Computer Science To activate or start (a program, for example).