ex·trav·a·sa·tion \ikˌstravəˈsāshən, (ˌ)ekˌ-\noun (-s) Etymology:extravasate (I) + -ion 1.: the action of extravasating : the condition of being extravasated < the extravasation of lava from a volcano > : effusion, eruption 2.: an extravasated fluid or a deposit formed from extravasation : extravasate