What's "took up a collection" mean? Is this an idiom?

Rebecca

"Took up a collection" is not an idiom! To "take up a collection" usually means to get monetary donations from people intentionally and for a certain cause or purpose, usually charity! One "collects" the money. Ex: The family took up a collection to send you to study overseas. Ex: We'll be taking up a collection for the charity this weekend at the fair.