Question

I'll need to brush up (on) my Greek before my trip to Athens.

Accepted Answer

(idiomatichttps://en.wiktionary.org/wiki/Appendix:Glossary#idiomatic) To reviewhttps://en.wiktionary.org/wiki/review; to improvehttps://en.wiktionary.org/wiki/improve an existing but rustyhttps://en.wiktionary.org/wiki/rusty or underdeveloped skillhttps://en.wiktionary.org/wiki/skill.

Sentence	I'll need to brush up (on) my Greek before my trip to Athens.
Definition	( idiomatic https://en.wiktionary.org/wiki/Appendix:Glossary#idiomatic ) To review https://en.wiktionary.org/wiki/review ; to improve https://en.wiktionary.org/wiki/improve an existing but rusty https://en.wiktionary.org/wiki/rusty or underdeveloped skill https://en.wiktionary.org/wiki/skill .

Brush Greek Trip Athens Existing Underdeveloped