- something that is collected; a group of objects or an amount of material accumulated in one location, especially for some purpose or as a result of some process:
a stamp collection;
a collection of unclaimed hats in the checkroom;
a collection of books on Churchill.

- the works of art constituting the holdings of an art museum:
a history of the museum and of the collection.

- the gathered or exhibited works of a single painter, sculptor, etc.:
an excellent Picasso collection.

- collections,  the various holdings of an art museum organized by category, as painting, sculpture, works on paper, photography, or film:
the director of the collections.

- the clothes or other items produced by a designer, especially for a seasonal line:
the spring collection.

And so on. :-)