an·es·the·sia also an·aes·the·sia (?n??s-th??zh?)n.1. Total or partial loss of sensation, especially tactile sensibility, induced by disease, injury, acupuncture, or an anesthetic, such as chloroform or nitrous oxide.2. Local or general insensibility to pain with or without the loss of consciousness, induced by an anesthetic.3. Medication that induces partial or total loss of sensation and may be topical, local, regional, or general, depending on the method of administration and area of the body affected.[New Latin anaesth?sia, from Greek anaisth?si?, insensibility : an-, without; see a-1 + aisth?sis, feeling (from aisthanesthai, aisth?-, to feel; see au- in Indo-European roots).]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.anesthesia (?æn?s??i?z??) n (Medicine) the usual US spelling of anaesthesiaCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014an?es?the?sia or an?aes?the?sia (?æn ?s??i ??) n. 1. general or localized insensibility, induced by drugs or other intervention and used in surgery or other painful procedures. 2. general loss of the senses of feeling, as pain, temperature, and touch. [1715?25;