'Indelible ink' definitions:

Definition of 'indelible ink'

noun

Ink that cannot be erased or washed away

From: GCIDE

Indelible \In*del"i*ble\, a. [L. indelebilis; pref. in- not + delebilis capable of being destroyed: cf. F. ind['e]l['e]bile. See In- not, and Deleble.] [Formerly written also indeleble, which accords with the etymology of the word.] [1913 Webster]
1. That can not be removed, washed away, blotted out, or effaced; incapable of being canceled, lost, or forgotten; as, indelible characters; an indelible stain; an indelible impression on the memory. [1913 Webster]
2. That can not be annulled; indestructible. [R.] [1913 Webster]
They are endued with indelible power from above. --Sprat. [1913 Webster]
Indelible colors, fast colors which do not fade or tarnish by exposure.
Indelible ink, an ink not obliterated by washing; esp., a solution of silver nitrate.
Syn: Fixed; fast; permanent; ineffaceable. -- {In*del"i*ble*ness}, n. -- {In*del"i*bly}, adv. [1913 Webster]
Indelibly stamped and impressed. --J. Ellis. [1913 Webster]