buff up

== English == === Pronunciation === === Verb === buff up (third-person singular simple present buffs up, present participle buffing up, simple past and past participle buffed up) (transitive, idiomatic) To improve. (transitive) To shine; to make shiny. (intransitive, idiomatic) To become more muscular. (intransitive, idiomatic) To study hard to learn a particular subject. Synonym: cram