'alumina-deficient' is a modern compound formed from 'alumina' and 'deficient'. 'Alumina' is the chemical name for aluminium oxide and originates from Neo-Latin 'alumina' (from Latin 'alumen' meaning 'bitter salt' or 'alum'), while 'deficient' comes from Latin 'deficere' via past participle forms meaning 'to be lacking'.

'alumina' entered scientific English usage in Neo-Latin/early modern chemistry from Latin 'alumen' and became the standard chemical term 'alumina'; 'deficient' developed from Latin 'deficiens' into Middle English/Old French forms and into modern English 'deficient'. The compound usage simply combines the two modern English words.

Individually, 'alumina' originally named a salt-related substance and later settled on the oxide Al2O3 in chemistry; 'deficient' originally meant 'falling away' or 'lacking' and retained the sense of 'insufficient'. Together they now specifically mean 'lacking sufficient alumina'.