'microamount' originates from the combining form 'micro-' (from Greek 'mikros' meaning 'small') and the English noun 'amount' (from Old French/Middle English meaning 'sum' or 'quantity').

'microamount' is a modern English coinage formed by compounding the productive prefix 'micro-' with the established noun 'amount' rather than evolving through earlier single-word stages.

Individually, 'micro-' originally meant 'small' and 'amount' meant 'sum' or 'quantity'; when combined in modern usage they specifically denote 'an extremely small quantity'.