This is what Wikipedia says on the subject:

A still life (plural still lifes) is a work of art depicting mostly inanimate subject matter, typically commonplace objects which may be either natural (food, flowers, plants, rocks, or shells) or man-made (drinking glasses, books, vases, jewelry, coins, pipes, and so on) in an artificial setting.

This week is stilleben week! Arrange your objects, light them and shoot :)