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ruffle up (something)
To mess up the smooth surface of something by making individual parts stand on end. A noun or pronoun can also be used between "ruffle" and "up." The cat really hates it if you ruffle up its fur by stroking it back to front. My uncle always ruffles my hair up when he sees me.
ruffle something up
to raise something, such as feathers, up or outward. The bird ruffled its feathers up and started to preen. It ruffled up its feathers.
To make some surface less smooth by partially lifting the individual parts that make up that surface: The wind ruffled up the bird's feathers. Don't ruffle my hair up.