'abomasal' originates from the word 'abomasum', which is derived from New Latin, specifically the word 'abomasus', where 'ab-' meant 'away from' and 'omasus' referred to 'the third stomach of a ruminant'.

'abomasus' transformed into the modern English word 'abomasum', and the adjective form 'abomasal' was derived from it.

Initially, it referred specifically to the fourth stomach of ruminants, and this meaning has largely remained the same in modern usage.