'aluminum-deficient' originates from modern English, specifically a compound of 'aluminum' (the metallic element name) and 'deficient' (meaning 'lacking').

'aluminum' derives from Latin 'alumen' (meaning 'bitter salt' or 'alum') and entered English via New Latin and scientific usage, later yielding the modern English forms 'aluminium' (British) and 'aluminum' (American). 'deficient' comes from Latin 'deficere' (to fail), passed into Old French and Middle English before becoming the modern English adjective 'deficient'. The compound 'aluminum-deficient' is a straightforward modern English formation combining the element name with 'deficient'.

Initially, 'aluminum' named a substance related to 'alum' and 'deficient' meant 'lacking' or 'failing'; combined as a compound they retain the literal current meaning 'lacking aluminum' with little semantic shift.