As a noun ratchet
is a pawl, click or detent for holding or propelling a ratchet wheel, or ratch, etc.
As a verb ratchet
is to cause to become incremented or decremented.
As an adjective ratchet
is (us|slang) ghetto (unseemly and indecorous).
As a symbol cog is
the iso 3166-1 three-letter (alpha-3) code for the republic of the congo.