"gridiron," 1680s, from French gril, from Old French greil, alteration of graille "grill, frating, railings, fencing," from Latin craticula "gridiron, small griddle," diminutive of cratis "wickerwork," perhaps from PIE *kert- "to turn, entwine." In many instances, Modern English grill is a shortened form of grille, such as "chrome front of an automobile."

"to broil on a grill," 1660s, from grill, n.; figurative sense from 1842, and the specific (transitive) sense of "to subject to intense questioning" is first attested 1894. Related: Grilled; grilling.