The term pleonasm is most often, however, employed as synonymous with tautology.
From the en.wikipedia.org
And while chillax may be a pleonasm, it is most definitely a sign of the times.
From the economist.com
In many cases of semantic pleonasm, the status of a word as pleonastic depends on context.
From the en.wikipedia.org
Semantic pleonasm is more a question of style and usage than grammar.
From the en.wikipedia.org
Syntactic pleonasm occurs when the grammar of a language makes certain function words optional.
From the en.wikipedia.org
Yogi Berra's humorous quote above about not making predictions isn't really a pleonasm, but rather an ironicplay on words.
From the en.wikipedia.org
Tautology and pleonasm are not the same thing.
From the en.wikipedia.org
Federal foreign policy is a pleonasm.
From the theatlantic.com
Linguists usually call this redundancy to avoid confusion with syntactic pleonasm, a more important phenomenon for theoretical linguistics.
From the en.wikipedia.org
More examples
Using more words than necessary; "a tiny little child"
Pleonasm is the use of more words or word-parts than is necessary for clear expression: examples are black darkness, burning fire, digital download or redundant pleonasm. Such redundancy is, by traditional rhetorical criteria, a manifestation of tautology. ...
Redundancy in wording; A phrase involving pleonasm, that is, a phrase in which one or more words are redundant as their meaning is expressed elsewhere in the phrase
The use of a superfluity of words, often deliberately, for emphasis. "I've never seen anything more obscene in all my 80 years on this Earth."
Unnecessary verbiage, redundancy as in "It was a dark and lightless night."
A habit of speech or writing in which an idea repeats itself in a single sentence, i.e., a redundancy. For example, "tiny little town" is a pleonasm, as opposed to "tiny town" or "little town. ...
An expression which, if omitted, would not change the meaning. Its use is usually considered a fault, but is sometimes acceptable for emphasis.
A compound expression that links an equivocal with an unequivocal term by putting one of them in parentheses after the other -- for example, "income (economic income)" to represent one of the meanings of "income."
The use of more words than necessary to express an idea.