(a)esthesia
esthesia (US) or aesthesia (es-THEE-zhuh, es-THEE-zhee-uh) - n., the ability to experience sensation or perception.
This could either be a 19th century borrowing directly from Greek aistēsía, sensation or perception, or a 20th century back-formation from an(a)esthesia, itself borrowed around 1720 from New Latin, from Greek anaisthēsía, want of feeling, from an-, not + the same root -- dictionaries disagree on the matter. They all agree, however, that the negative form is much more common.
---L.
This could either be a 19th century borrowing directly from Greek aistēsía, sensation or perception, or a 20th century back-formation from an(a)esthesia, itself borrowed around 1720 from New Latin, from Greek anaisthēsía, want of feeling, from an-, not + the same root -- dictionaries disagree on the matter. They all agree, however, that the negative form is much more common.
---L.