Possible Clues:

• Disturb, as hair
• Muss one's hair, e.g.
• From America's point of view, the French mess up ...
• Rumple (hair)
• Treat roughly? In our opinion that's extremely loathsome
• Rumple, make untidy as with hair
• Mess around, having to employ learner inside
• Ruffle - disarrange
• Cut off the top and make a mess of the louse
• Disorder