A phrase that combines a verb with a preposition or adverb or both and that functions as a verb whose meaning is different from the combined meanings of the individual words.
Phrasal Verb:
keep something down
Meaning / Example:
1. to make the level of noise lower and keep it lower. > Please keep it down. You are just too noisy.
2. to retain food in one's stomach rather than throwing it up. > I've got the flu and I can't keep any food down.
3. to keep spending under control. > I work hard to keep expenses down.