An applicator is a tool designed to put something exactly where it needs to go. The cotton swab you use to apply ointment to a cut is an applicator. The roller attached to a bottle of lip gloss is an applicator. The long stick that comes with wood glue is an applicator.

Applicators solve a practical problem: how do you get the right amount of something in the right spot without making a mess? A glue stick has a built-in applicator that twists up so you can spread glue smoothly on paper. A roll-on deodorant has an applicator ball that spreads the product evenly. Paint rollers are applicators that cover large wall surfaces faster than brushes can.

Different jobs and hobbies use specialized applicators: a farmer might use a fertilizer applicator to spread nutrients across fields, while an artist might use a foam applicator to blend pastels. Sometimes the applicator matters as much as what you're applying. Anyone who's tried spreading peanut butter with a spoon instead of a knife knows that having the right applicator makes all the difference.