What is Frost ?
Frost is (noun) 1. a white covering on the ground, trees, etc., when the temperature is below freezing The garden was white with frost. 2. cold weather, when the temperature is below freezing There was a hard frost last night. There’s a touch of frost in the air. A late frost can damage young plants. ten degrees of frost ten degrees below zero (verb) 1. to cover with frost; to be damaged by frost to frost over to become covered with frost 2. to frost a cake US to put icing on a cake
source: Easier English, Student Dictionary Upper Intermediate Level