fall a prey
The idiom "to fall a prey" means to become a victim or to be taken advantage of by someone or something. It implies being trapped or helpless in the face of a situation or a person's actions.
Beware that you do not fall a prey to the highwaymen who stalk these roads.
If you are too trusting, you will fall prey to con artists and internet scams.
Ever since the funeral, Aunt Bessy was liable to fall apart at the least mention of Uncle Billy.
My Favorite IDIOM Is, When Pigs Fly.
Idiom
"She's feeling under the weather" is an example of an idiom, meaning that someone is feeling unwell or sick.
That phrase must be an idiom, because I can't understand what it means."It's raining cats and dogs" is an idiom for "it's raining really hard.""I am learning about idioms in English class."Timmy was the apple of my eye".This sentence is an example of an idiom.
An idiom usually is a sentence, or part of one. It certainly can be used as part of a sentence. The way to tell if it's an idiom is if it makes sense the way it's literally written.
yes, it is.
The sentence is not, because an idiom is usually a phrase. The idiom is "do lunch," which means to have lunch together, usually while discussing business.
That IS a sentence.