'bajada' originates from Spanish, specifically the noun 'bajada' (from the verb 'bajar'), where the verb 'bajar' meant 'to go down' or 'to descend'.

'bajada' developed from Old Spanish forms such as 'baixada' and ultimately derives from Vulgar/late Latin roots related to 'bassus'/'bassare' meaning 'low' or 'to make low'. It entered English as a loanword in geomorphology to name the coalesced alluvial slopes.

Initially in Spanish it meant 'a lowering, descent, or downhill place'; in English it retained the sense of 'descent' but specialized in geology to mean the broad slope formed by merging alluvial fans.