To kiss means to touch someone with your lips as a sign of love, affection, greeting, or respect. Parents kiss their children goodnight, friends might kiss each other on the cheek when saying hello in some cultures, and people may kiss someone they care about.

Kissing carries different meanings depending on context and culture. A quick peck on the forehead shows caring and comfort. In many European countries, friends greet each other with kisses on both cheeks, while in America, this would seem unusual outside of family. Some people kiss their hand and then touch a religious object or photograph as a gesture of reverence.

The phrase kiss goodbye means to accept that something is lost or over, like when a student who didn't study might kiss their A goodbye. To kiss up to someone means to flatter them excessively, often to gain favor, which people generally find annoying and insincere.

You might also see kiss as an acronym: KISS stands for “Keep It Simple, Stupid,” a reminder that the simplest solution often works best. Engineers, writers, and problem-solvers use this principle to avoid making things more complicated than necessary.