Etymology The noun is derived from fine (“particularly slender”) + tooth (“sharp projection”) + comb. The verb is derived from the noun.
1
A comb with fine, closely spaced teeth, especially one used for removing head lice and their nits (eggs) from the hair; a nit comb.
The practice of combing the heads of children too frequently with a fine tooth comb is a bad one, as the points of the teeth are quite sure to scratch and irritate the scalp, and are almost sure to produce scurf or dandruff.1858, Lola Montez, The Arts of Beauty, Chapter 21:
'Member dat rainy eve dat I drove you out, Wid nothing but a fine tooth comb?1902, Hughie Cannon, “Bill Bailey, Won't You Please Come Home?”:
The police went through his possessions with a fine-tooth comb.
If you had to make some verses on the topics of the day, You would read the morning papers rather fully; For you’d like to find a theme to make your readers shout: “Hooray!” And to make your Dear Employer say: “That’s bully!” You would scan aforesaid journals with a very fine-tooth comb (With the metaphors I’m something of a mixer.) For a nifty little subject you could pad into a pome; And you’d have to be about it pretty quick, sir.1912, Franklin P. Adams, Of Course You Would:
Etymology The noun is derived from fine (“particularly slender”) + tooth (“sharp projection”) + comb. The verb is derived from the noun.
1
Dated To comb or go through (hair, an animal's fur, etc.) with a comb having fine, closely spaced teeth.
2
Figuratively To search (something or somewhere) meticulously.
"There's one other way of discovering the writer,—find a Rem-Smith typewriter with an alignment imperfect in just this way." "Yes," said Astro. "We might begin and fine-tooth-comb the city for it.:Template:.."1912, Frank Gelett Burgess, The Master of Mysteries, Mrs. Stellery's Letters: