Creep worried about one puncture (6)
I believe the answer is:
pierce
'puncture' is the definition.
(I know that pierce is a is a more specific form of the action of puncture)
'creep worried about one' is the wordplay.
'worried' indicates an anagram (worry can mean to interfere with or disturb).
'about' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'creep' with letters rearranged gives 'perce'.
'perce' going around 'i' is 'PIERCE'.
(Other definitions for pierce that I've seen before include "Possibly drill" , "Make hole in with something sharp" , "boy?" , "Penetrate as with sharp object" , "Cut through with a sharp instrument" .)