See comb in Webster's New World Roget's A-Z Thesaurus II
verb
To make a thorough search of:
forage, ransack, rummage, scour2. (Slang) shake down. Idioms: beat the bushes, leave no stone unturned, look (or search) high and low, look (or search) up and down, turn inside out, turn upside down. See investigate