'apron-shaped' originates from Modern English, formed by combining the noun 'apron' and the adjective-forming element '-shaped' (from the past participle 'shaped', derived from the verb 'shape').

'apron' comes from Middle English 'napron', from Old French 'naperon' (diminutive of 'nape' meaning tablecloth); rebracketing of 'a napron' to 'an apron' produced the modern form. The suffix '-shaped' developed in English by using the past participle 'shaped' adjectivally (as in earlier compounds like 'bell-shaped'), and the compound 'apron-shaped' arose by straightforward compounding of these elements.

Originally 'apron' referred to a small cloth or table covering and later came to denote the garment worn over the front of the body; the compound 'apron-shaped' has consistently meant 'in the shape of an apron' in modern usage.