club soda or fruit juice used to mix with alcohol
"The bartender added a splash of lemon-lime mixer to the whiskey before serving it neat."
electronic equipment that mixes two or more input signals to give a single output signal
"The audio engineer adjusted the settings on the mixer to combine the vocals and guitar tracks into a single output channel."
a kitchen utensil that is used for mixing foods
"She reached for the hand mixer to blend the ingredients in her bowl."
One who, or a device that, mixes or merges things together.
"The wedding host served as an enthusiastic mixer, ensuring every guest mingled with someone new."
In plain English: A mixer is an electrical tool that spins beaters to quickly whip up ingredients for things like cake batter, frosting, or mashed potatoes.
"The kitchen mixer made baking cookies much easier for her."
Usage: A mixer can refer to either the person operating an event's drinks or any mechanical device used to combine ingredients and liquids. Use this word specifically for tools designed to blend substances rather than general containers like bowls or blenders which have different primary functions.
The word mixer is a modern compound formed by combining Little Mix with the suffix -er to describe a member of that specific girl group. It was first used as an informal nickname for the band rather than referring to a kitchen appliance or device for blending ingredients.