1. To remove a liquid through evaporation as a result of cooking. A noun or pronoun can be used between "cook" and "off." You'll need to cook the excess water off before the solution can be used.
2. To be removed (from something) through evaporation as a result of cooking. A noun or pronoun can be used between "cook" and "off." Even though there is cognac in the recipe, the alcohol cooks off when the dish is being cooked.
3. To remove the safety pin and lever from a grenade and begin reducing the delay before it explodes. A noun or pronoun can be used between "cook" and "off." The soldier attempted to cook off the grenade so that it exploded on impact, but it ended up going off in midair. As a result of the incident with the grenades, soldiers are no longer instructed or taught how to cook them off.
4. Of explosives or ammunition, to fire or detonate prematurely or unintentionally as a result of excess heat in the surrounding environment. Military forces in the desert have had to start keeping their ammunition refrigerated during transport to avoid having it cook off in the extreme heat.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.