To waste one’s breath could be compared to banging one’s head against a brick wall or talking to a brick wall (or tree). If someone is wasting their breath they might be told to save their breath because they are wasting words. All these idioms hold the same basic meaning.
Meaning of Idiom “Waste One’s Breath”
1. offer advice or opinions that will never be heeded or agreed with. 1Jarvie, Gordon. Bloomsbury Dictionary of Idioms. United Kingdom, Bloomsbury Publishing, 2009.,2The Wordsworth Dictionary of Idioms. United Kingdom, Wordsworth, 1993.
2. to speak in vain. 3Ammer, Christine. The American Heritage Dictionary of Idioms: American English Idiomatic Expressions & Phrases. United States, Houghton Mifflin Harcourt, 2013.
3. to speak when no one will listen or pay attention to what one is saying. 4Idioms in the News – 1,000 Phrases, Real Examples. N.p., Peter Bengelsdorf.
4. to say something that is sure to be ignored. 5Cambridge Dictionary of American Idioms. Germany, Cambridge University Press, 2003.
5. to say something to someone or speak to someone when it is not required or desired.
This idiom is often used in the negative, as in “Don’t waste your breath.” Waste of breath is also a possible variant.
Sentence Examples
“I’m not going to bother trying to convince you. I’m obviously wasting my breath.”
“You’re wasting your breath with Dad. He’s never going to agree to get a dog. You have to talk to mom. She’ll wear him down.”
“I talked to the police about my missing bike.” “That was a waste of breath. They might take a report but they aren’t going to look for a bicycle.”
“Don’t waste your breath on these idiots. They are too ignorant to ever listen to what you’re saying.”
“I think I convinced Martin to let you go to that conference in Philadelphia.” “Sorry, you wasted your breath. I can’t go, as it turns out.”
“Where are these missing pages?” “You’re wasting your breath. He won’t tell us. He doesn’t have to.” — Indiana Jones and the Last Crusade (1989)
Origin
The original version of this idiom was “words of waste” an obsolete version of waste of words, used since the 1400s and still used and understood today. 6“Waste, N.” Oxford English Dictionary, Oxford UP, December 2024, https://doi.org/10.1093/OED/6694652496. Waste one’s breath was first seen in print in 1667. 7Ammer, Christine. The American Heritage Dictionary of Idioms: American English Idiomatic Expressions & Phrases. United States, Houghton Mifflin Harcourt, 2013.
Waste has been used to mean “useless expenditure or consumption, squandering (of money, goods, time, effort, etc.)” since the 1200s. 8“Waste, N.” Oxford English Dictionary, Oxford UP, December 2024, https://doi.org/10.1093/OED/6694652496. Since we must breath to be able to talk, the allusion in the idiom is that one is uselessly expending their air by talking to someone who cannot be convinced.