The person kept saying the same thing over and over which had no meaning so it was tautology.
Tautology is the useless repetition of words. I am going to the mall or I am not going to the mall is a tautology. Tautology is not simply the useless repetition of words. It is more about redundancy. The example above is tautology but it is because the phrase is redundant. "I may go go the mall today." implies that I may not to to the mall today. To include that I may not would be tautology. Another example of tautology is when you have two words whose meaning is the same used in conjunction. "Free gift" and "unsolved mystery" are tautology. The words are synonymous and therefore they are redundant.
Redundancy in speech is called tautology. Tautology involves using different words that essentially mean the same thing in a sentence, adding no extra meaning or understanding.
A tautology is a statement that is always true, regardless of the circumstances or conditions.
Two consecutive words in the one sentence that mean the same thing are called "redundant expressions."
Wittengstin
THE TRUTH
a tautology
A repetitious and overwritten sentence is often referred to as a pleonasm or tautology, where unnecessary words or phrases are used that do not add any additional meaning to the sentence. Editing such sentences can help improve clarity and conciseness in writing.
The antonym of an oxymoron is a tautology. For example: "almost exactly" is an oxymoron. "Tiny little" is a tautology.
somnolent sleepiness is an example of tautology in ransom of red chief
I guess you could claim one opposite of a tautology is an oxymoron.
tautology