He slicked his hair back with mousse, but the cowlick still stuck up.
He moussed his hair in the morning and then washed it out at night.
Origin of mousse
- French foam, mousse from Old French moss, foam partly of Germanic origin and partly from Latin mulsa hydromel from feminine of mulsus honey-sweet melit- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition