There are tongueless characters in A Song of Ice and Fire, meaning that they have had their tongues torn out by the roots at some point. It is a life changing event. A toungless person is disadvantaged by being rendered mute, and can tell no tales.
A tongue can be torn out with hot pincers.  Sometimes people have their tongue removed to subjugate and silence them. Removal of the tongue also serves as a torture technique, as well as a very cruel, severe and permanent, punishment - as they are left to live the rest of their lives without a tongue, diminishing their quality of life. A tongue can also be removed for vengeance. Sometimes a person’s tongue is removed under torture prior to being killed.
The mere threat to rip out tongues can be extremely effective. 
Characters left alive with no tongue
- Lelia Lannister – tongue torn out, lips, ears, eyelids removed by Shrike
- King Harmund III Hoare - Shrike himself took the deposed king's tongue so he may never again speak "lies and blasphemies". 
- Ramsay Snow’s maternal uncle – Roose Bolton cuts out his tongue to silence him about Ramsay’s birth 
- Dusky woman – tongue torn out.
- Little birds – child spies with tongues removed.
- Crew of the Silence - Euron Greyjoy's infamous mutes
- Ser Ilyn Payne – tongue torn out by King Aerys II Targaryen
- Grunt – lost his tongue for speaking carelessly in Lord Roose Bolton’s hearing.
- Falia Flowers – tongue torn out by Euron Greyjoy .
- Envoy sent by Mance Rayder to Craster - Craster cut out his tongue.
Characters de-tongued and killed
- Lady Serala of Myr - was burned alive, though her tongue was torn out first. 
- Brother Clement - tongue cut out by attackers during the raid on Saltpans , in mockery of his vow of silence.
- Hagon Hoare - before being hanged, suffered the same mutilations which had been done to Lelia Lannister 
- A member of the Long Lances - Daario cuts out his tongue and feeds it to a yellow dog 
- Captain of the Ghiscari Dawn - had his tongue torn out for saying to Victarion Greyjoy that Daenerys Targaryen was dead, before being thrown overboard. 
Characters who remove tongues
- King Aerys II Targaryen
- Euron Greyjoy
- Roose Bolton
- Victarion Greyjoy
- Daario Naharis
A Feast for Crows
Sweetrobin complains about Marillion’s singing and says to Alayne Stone that her father should have cut his tongue out and that he told him to, but he wouldn’t. Alayne thinks to herself that Marillion needed his tongue so that he could confess to her aunts murder. 
Jaime recalls that Ser Ilyn was heard saying that it was Tywin Lannister who truly ruled the Seven Kingdoms, rather than King Aerys II Targaryen. The king had Ilyn's tongue torn out with hot pincers for the comment. 
The normally placid Tommen becomes furious when his mother says she would gladly have Margaery Tyrell’s tongue torn out. To punish him she orders that Tommen is to whip Pate and if His Grace refuses or protests, Qyburn is to be summoned to remove Pates tongue. 
A Dance with Dragons
When Illyrio Mopatis tells Tyrion Lannister that there are those in Westeros who would say that killing Tywin Lannister was merely a good beginning Tyrion tells him not to say that in his sister’s hearing, or they will find themselves short of a tongue. 
The Winds of Winter
At least rip out his tongue. This man’s lie could destroy us all, Magnificence. 
Lie to me, and I’ll take your tongue. 
Theon Greyjoy’s thoughts
I should have the tongues removed from all my friends.
– Jaime, to Ser Ilyn
- A Feast for Crows, Chapter 27, Jaime III.
- A Dance with Dragons, Chapter 56, The Iron Suitor.
- A Feast for Crows, Chapter 17, Cersei IV.
- A Dance with Dragons, Chapter 19, Davos III.
- A Feast for Crows, Chapter 9, Brienne II.
- A Feast for Crows, Chapter 31, Brienne VI.
- A Feast for Crows, Chapter 29, The Reaver.
- A Storm of Swords, Chapter 45, Catelyn V.
- The World of Ice & Fire, The Black Blood.
- A Dance with Dragons, Chapter 32, Reek III.
- A Game of Thrones, Chapter 32, Arya III.
- A Dance with Dragons, Chapter 11, Daenerys II.
- Batlicon Reading notes
- A Clash of Kings, Chapter 23, Jon III.
- A Dance with Dragons, Chapter 23, Daenerys IV.
- A Dance with Dragons, Chapter 63, Victarion I.
- A Game of Thrones, Chapter 15, Sansa I.
- A Feast for Crows, Chapter 18, The Iron Captain.
- A Feast for Crows, Chapter 3, Cersei I.
- A Feast for Crows, Chapter 10, Sansa I.
- A Feast for Crows, Chapter 12, Cersei III.
- A Feast for Crows, Chapter 23, Alayne I.
- A Storm of Swords, Chapter 11, Jaime II.
- A Feast for Crows, Chapter 36, Cersei VIII.
- A Dance with Dragons, Chapter 1, Tyrion I.
- A Dance with Dragons, Chapter 8, Tyrion III.
- A Dance with Dragons, Chapter 37, The Prince of Winterfell.
- Batlicon Reading notes
- A Feast for Crows, Chapter 7, Cersei II.
- A Dance with Dragons, Chapter 20, Reek II.