From Longman Dictionary of Contemporary Englishlunch hourˈlunch hour noun [countable] DFthe period of time in the middle of the day when people stop working in order to eat I did the shopping during my lunch hour.
Examples from the Corpus
lunch hour• Walk for fifteen minutes each lunch hour.• During her lunch hour she shopped, deliberately avoiding the part of town in which Giles's office was situated.• He had roamed Queenstown during his lunch hour at the beginning of the week before he could find a roaster for sale.• Friday: the long lunch hour at the York.• Nearly everyone, however, even on casual Friday, is drinking soda or tea during the lunch hour.• I went to over the lunch hour. 