deaf / def/ • adj. lacking the power of hearing or having impaired hearing: [as pl. n.] (the deaf) subtitles for the deaf. ∎  unwilling or unable to hear or pay attention to something: deaf to advice.PHRASES: (as) deaf as a post completely or extremely deaf.fall on deaf ears (of a statement or request) be ignored.turn a deaf ear refuse to listen or respond to a statement or request.DERIVATIVES: deaf·ness n.ORIGIN: Old English dēaf, of Germanic origin; related to Dutch doof and German taub, from an Indo-European root shared by Greek tuphlos ‘blind.’

deaf deaf as an adder proverbial expression meaning very deaf, probably originally with biblical allusion to the ‘deaf adder that stoppeth her ear’ of Psalm 58:4–5, ‘Which will not hearken to the voice of charmers: charming never so wisely.’
a deaf husband and a blind wife are always a happy couple proverbial saying, late 16th century, meaning that each will remain unaware of drawbacks in the other. The saying is sometimes reversed to a blind husband and a deaf wife.
there's none so deaf as those who will not hear proverbial saying, mid 16th century, used to refer to someone who chooses not to listen to unwelcome information. (Compare there's none so blind as those who will not see.)

deaf OE. dēaf = OS. dōf (Du. doof), OHG. toup (G. taub), ON. daufr, Goth. daufs :- Gmc. *dauƀaz. The IE. base *dhoubh- *dheubh- *dhubh- is repr. also by Gr. tuphlós blind. The pronunc. with a long vowel was still gen. current in XVIII, and remains widely diffused dial. and in U.S.
Hence deafen XVI; see -EN 5.