comb

with a fine-tooth comb

if you examine something with a fine-tooth comb, you examine every part of it very carefully. I'd advise you to examine your insurance policy with a fine-tooth comb to make sure you're covered if you take your car abroad.

---

go over something with a fine-tooth comb

to examine every part of something very carefully. My accountant is going over my tax return with a fine-tooth comb.

Usage notes: also used in the form fine-toothed comb

See also: over