What does “auffrischen” mean in German?

Auffrischen means to refresh or touch something up — to bring it back to how it was, or simply give it a boost. It is built from frisch (“fresh”) with the separable prefix auf-, and the prefix does real work: it adds the sense of restoring freshness rather than creating it from scratch. Germans use the same verb for a haircolour touch-up, a language course, a booster shot (Auffrischimpfung), and a coat of paint.

In the clip, a sibling sees a dramatically lighter head of hair and blurts out: “Ich dachte, sie frischt ihr Rot einfach nur auf beim Friseur” — “I thought she was just touching up her red at the hairdresser.” The verb splits in that sentence: frischt … auf wraps around the object. That separable split is worth noticing: when auffrischen is conjugated, auf jumps to the end — ich frische meine Kenntnisse auf (“I’m brushing up my knowledge”), er hat seinen Wortschatz aufgefrischt (“he refreshed his vocabulary”). Same verb, whether it is hair, grammar, or a vaccine.