The phrase no ifs, ands, or buts is a list of words that are often used to begin a sentence that is an explanation or excuse for bad behavior or for not fulfilling an obligation. Most often, no ifs, ands or buts is one of those phrases that is expressed in informal, spoken English.
If someone says they don’t want to hear no ifs, ands, or buts then that means they don’t want to hear any excuses. Example: Jimmy has been relaxing all morning, so his mother said to him, “It’s time for you to do some house chores.
This expression uses the conjunctions to stand for the conditions and objections that they introduce. The earliest phrase to appear was ifs and ands in the 1600s. This phrase is actually an emphatic redundancy, for and often meant “if.” But was tacked on to this pair soon afterward.
Partial sources: Dictionary.com, Google.com, Cartoon credit: Mark Anderson