1721, "loss of feeling," medical Latin, from Greek anaisthēsia "want of feeling or perception, lack of sensation (to pleasure or pain)," abstract noun from an- "without" (see an- (1)) + aisthēsis "feeling," from PIE root *au- "to perceive." For the abstract noun ending, see -ia. As "a procedure for the prevention of pain in surgical operations," from 1846. Aesthesia "capacity for feeling" is attested in English from 1853, perhaps a back-formation.
"pertaining to or situated near a tail," 1660s, from Latin cauda "tail of an animal," which is of unknown origin, + -al (1).
type of barbiturate, originally used to calm patients before anesthesia and operation, 1930, proprietary name of pentobarbitone sodium, formed from letters and syllables from N(a) "sodium" + full chemical name 5-ethyl-5-1-methylbutyl barbiturate.
1908, from anesthesia + -ology.
Anesthesiology. This is the new term adopted by the University of Illinois defining "the science that treats of the means and methods of producing in man or animal various degrees of insensibility with or without hypnosis." [Medical Herald, January, 1912]
also kinaesthesia, "the sense of muscular movement," 1888, Modern Latin compound of elements from Greek kinein "to set in motion; to move" (from PIE root *keie- "to set in motion") + aisthēsis "perception" (see anesthesia). Earlier was kinaesthesis (1880).