Possible Clues:

• If absolutely necessary
• When a girl may scream in case of necessity
• An easy goal? Check, if need be
• A gimme? Check if absolutely necessary
• How a little blow and a little length might do for a little nipper
• In case of necessity
• In time of difficulty or necessity - nip it
• If necessary this is what the nipper might be at
• In emergency, move slowly after a knock
• A bit of plumbing can be installed on island if really necessary