mousser

Mousser is a French verb meaning to foam, froth, or bubble. It describes liquids that form bubbles or a layer of foam, such as sea spray, beer, soups, or beverages that begin to effervesce. The term comes from the noun mousse (foam) and the common verb ending -er.

In conjugation, mousser is an intransitive verb: je mousse, tu mousses, il mousse, nous moussons, vous moussez, ils moussent. The past participle is moussé; the present participle is moussant. Related adjective forms include moussant (foaming) and mousseux (frothy, sparkling).

Mousser is distinct from the noun mousse, which denotes a whipped dessert or a creamy foam. Although related in meaning, mousse describes the foam itself or the dessert, while mousser denotes the action of forming foam.

In modern French, you may encounter phrases such as la mer mousse (the sea foams), le café mousse (the coffee foams), and des boissons qui moussent (beverages that foam). A related noun, mousseur, refers to a frothing device, such as un mousseur à lait, used to produce milk foam.

In English-language contexts, the verb is rarely used; translators typically render it as “to foam” or “to froth.” Related French forms include mousse (foam or dessert), moussant (foaming), and mousseux (frothy or sparkling).