'anaesthetize' originates from Greek, specifically the word 'anaisthēsia,' where 'an-' meant 'without' and 'aisthēsis' meant 'sensation.'

'anaisthēsia' transformed into the French word 'anesthésie,' and eventually became the modern English word 'anaesthetize' through medical Latin and English.

Initially, it meant 'to make insensible or without feeling,' but over time it evolved into its current meaning of 'to administer an anaesthetic to cause loss of sensation.'