The meaning and etymology of this single attestation pose a problem. The word seems to derive directly from a declined form of Latin aegritudo ('illness'), albeit as a hapax and with other Anglo-Norman derivatives of the aegrotus etymon (FEW 24,208a) taking the form of engrut, engrutement, etc. However, both FEW and DEAF suggest associating the word with the acer family, including AND egre ('bitter' sour') and egreté ('bitterness'), in which case it may be interpreted as a synonym to amertume, also mentioned in the same citation.