'antecedaneous' originates from Latin, specifically from the present-participle form 'antecedens' (from 'antecedere'), where 'ante-' meant 'before' and 'cedere' meant 'to go'.

'antecedens' (Latin) was used as an adjectival/participle form meaning 'going before'; through Late Latin and later Medieval/Modern English usage of 'antecedent', English formed the adjective 'antecedaneous' (by combining the stem with an adjectival suffix) to express the quality of preceding.

Initially, it meant 'going before' or 'preceding', and over time it retained this core sense, now used more formally to mean 'prior in time or order'.