When we ask for reasons in speaking, we can use the phrase why is that? In informal conversations we often say why’s that?: … The meaning of WHY is for what cause, reason, or purpose. How to use why in a sentence. 3.1Psychological significance and value in life. 3.2Origin and nature of biological life. 3.3Origins and ultimate fate of the universe. 3.4Scientific questions about the mind. 3.4.1Parapsychology. 3.5Nature of meaning in life. a. for what reason, purpose, or cause?: why are you here?. b. (used in indirect questions): tell me why you're here. /waɪ/ IPA guide Other forms: whys Definitions of why noun the cause or intention underlying an action or situation, especially in the phrase `the whys and wherefores' synonyms: wherefore Five key greenhouse gases are carbon dioxide, nitrous oxide, methane, chlorofluorocarbons, and water vapor. A simplified animation of the greenhouse effect. Credit: NASA/JPL-Caltech. WHY definition: 1. for what reason: 2. used to express surprise or anger: 3. the reasons for something. Learn more. Humans, rather, keep evolving, and our constant development is expressed in us increasingly asking about the meaning of life from one generation to the next. We cannot help but ask about the meaning of life and why we are here. To ask why we are here is to ask what it means to be human, to wonder whether life has a purpose or if we are the fleeting products of chance in a vast and indifferent universe. Philosophers, poets, scientists, and spiritual leaders have all grappled with this mystery. Learn the correct usage of why are and why is in English. Discover differences, examples, alternatives and tips for choosing the right phrase.