noun
plural lunches
a light meal eaten in the middle of the day [count]
When people do lunch they have lunch together. This is an informal phrase that is often associated with people in business.
eat/have someone or something for lunch
or eat someone's or something's lunch
US informal :to defeat someone or something very badly
lose your lunch
US slang :to throw up :vomit
no free lunch
The expression there is no free lunch or there is no such thing as a free lunch means that it is not possible to get something that is desired or valuable without having to pay for it in some way.
out to lunch
informal :not aware of what is really happening :too strange or confused to notice or understand what is really happening
verb
lunches; lunched; lunching
[no obj] :to eat lunch