lay figure

noun
1.
a jointed model of the human body, usually of wood, from which artists work in the absence of a living model.
2.
a similar figure used in shops to display costumes.
3.
a person of no importance, individuality, distinction, etc.; nonentity.
Origin
1785-95; lay, extracted from obsolete layman < Dutch leeman, variant of ledenman, equivalent to leden- (combining form of lid limb, cognate with Old English, Middle English lith) + man man1)
British Dictionary definitions for lay figure

lay figure

noun
1.
an artist's jointed dummy, used in place of a live model, esp for studying effects of drapery
2.
a person considered to be subservient or unimportant
Word Origin
C18: from obsolete layman, from Dutch leeman, literally: joint-man