the sentence was created/devised by the great Noam Chomsky. it demonstrates a sentence that is grammatically acceptable but without meaning.
however, some people believe that it does have a meaning.
The following is a quote I found by doing a yahoo search.
The sentence, "Colorless green ideas sleep furiously", was presented by Chomsky, as a great example of a series of words strung together randomly. Not only is it grammatical according to the lexical classification, and non-sense on a semantic level. Or so goes the claim. But is the claim correct?
A green idea is, according to well established usage of the word "green" is one that is an idea that is new and untried. Again, a colorless idea is one without vividness, dull and unexciting. So it follows that a colorless green idea is a new, untried idea that is without vividness, dull and unexciting. To sleep is, among other things, is to be in a state of dormancy or inactivity, or in a state of unconsciousness. To sleep furiously may seem a puzzling turn of phrase but one reflects that the mind in sleep often indeed moves furiously with ideas and images flickering in and out.
So what is the poet telling us? (One assumes that the quoted line is from the work of a poet working in a medium of studied precision and ambiguity. Or rather, as we shall see...) Very simply the poet seems to be saying that new ideas, not yet sharply defined, circulate in the unconscious, rapidly altering at a furious rate.
One is left then with a question. Why is this nice bit of poetic imagery cited by its author as a quintessentially meaningless sentence? Here we have an exquisite bit of irony. The author evidently has a turn for poetry, a turn which he turns his face against. And the hidden face, the denied self, has taken its revenge. The scientist has called on his creative self to exhibit a bit of nonsense. The poet denied has replied with a sentence, apparently meaningless, which is no such thing when listened to with an attentive ear. And yet consider; this sentence is a very intellectualized production - it is indeed "colorless". It was, we suspect, a new idea, a variant of a possibility, still new at the very moment of production, one occurring by chance in the froth of the unconscious.
In short, the cited sentence was a colorless green idea that had slept furiously.
