Impossible to remove, erase, or wash away; permanent: indelible ink.
Making a mark not easily erased or washed away: an indelible pen for labeling clothing.
Unable to be forgotten; memorable: an indelible memory.
[Alteration of earlier indeleble, from Latin indēlēbilis : in-, not; see in-1 + dēlēbilis, capable of being effaced (from dēlēre, to wipe out).] in·del'i·bil'i·ty, in·del'i·ble·ness n., in·del'i·bly adv.