'hoop-shaped' is a compound formed in English from 'hoop' + the past-participle/adjectival form 'shaped'. 'Hoop' originates from Old English 'hōp' (from Proto-Germanic *hupô) meaning 'ring' or 'bend', while 'shape' originates from Old English 'sceap'/'scieppan' (from Proto-Germanic *skap-, meaning 'form, create').

'Hoop' passed from Old English 'hōp' into Middle English as 'hoop' retaining the sense 'ring'; 'shape' developed from Old English roots into the noun and verb 'shape' in Middle English. The compound 'hoop-shaped' arose in Modern English by combining the noun 'hoop' with the participial adjective-form 'shaped' to describe something having the form of a hoop.

Initially the elements referred separately to a 'ring' ('hoop') and to forming ('shape'); over time the compound came to be used adjectivally to mean 'having the form of a hoop', a usage that has remained stable.