Did the Buddha really say that "life is suffering"?

I often see the first noble truth (*duḥkha*) stated as "life is suffering". I have yet to come across a passage in a Buddhist text which phrases it like this - mostly they don't talk about "life" in this sense. So where does the idea that "*life is suffering*" come from? There's been some discussion about the definition and translation of the word "*dukkha*" also. Is there a definitive definition?