1. 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" (Ford Madox Ford).
2. To appeal to or cite in support or justification.
3. To call for earnestly; solicit: invoked the help of a passing motorist.
4. To summon with incantations; conjure.
5. To resort to; use or apply: "Shamelessly, he invokes coincidence to achieve ironic effect" (Newsweek).
6. Computer Science. To activate or start (a program, for example).

[Middle English envoken, from Old French invoquer, from Latin invocāre : in-, in; see in-² + vocāre, to call.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.