If you rumple someone's hair, you move your hand backwards and forwards through it as your way of showing affection to them. I leaned forward to rumple his hair, but he jerked out of the way. = ruffle. to make hair, clothes etc less tidy (rompelen)
in disarray; extremely disorderly; "her clothing was disheveled"; "powder-smeared and frowzled"; "a rumpled unmade bed"; "a bed with tousled sheets"; "his brown hair was tousled, thick, and curly"- Al Spiers