'pyloric' originates from Late Latin/New Latin 'pyloricus', ultimately from Greek 'πυλωρός (pylōrós)', formed from 'πύλη (pylē)' meaning 'gate'.

'πυλωρός' passed into Latin as 'pylorus' (the anatomical term for the stomach's gate) and then into Late Latin/New Latin as 'pyloricus', which developed into the English adjective 'pyloric'.

Initially it meant 'of or pertaining to a gate' (in Greek), and over time it came to mean specifically 'relating to the pylorus (the stomach's gate)'.