'elbow-shaped' originates from Modern English as a compound of the noun 'elbow' and the past-participle adjective 'shaped'. 'elbow' itself comes from Old English 'eln-boga', where 'eln' meant 'forearm/ell' and 'boga' meant 'bend' or 'bow'; 'shape' comes from Old English verbs/nouns (e.g. 'sceppan') meaning 'to form' or 'creation'.

'elbow' changed from Old English 'eln-boga' to Middle English forms such as 'elbowe' and eventually to the modern English 'elbow'. 'shape' developed from Old English roots (e.g. 'sceppan'/'gesceap') through Middle English ('shapen') to modern 'shape', and the compound 'elbow-shaped' is a straightforward modern formation combining these elements.

Initially, 'elbow' referred specifically to the bend of the arm and 'shape' to form; combined, the phrase has long meant 'having the form of an elbow' and this descriptive meaning has remained stable into modern usage.