Transpire is from French transpirer, from Medieval Latin transpirare ('to breathe through'), from Latin trans- ('through') + spirare ('to breathe'); the sense 'to come to light, become known' arose from the metaphor of vapor escaping. Important recorded forms include transpirare (Latin), trans (Latin), and spirare (Latin). Morphologically, the trans- element contributes the sense of across, through, beyond, or change from one state into another. The semantic development is already visible in the history: an older concrete or specialized use was extended into the modern meaning rather than replaced by a separate origin. In current use it covers to happen or come to be known; to give off vapor through a surface. The wider family includes derived forms such as transpiration and transpirable and related words such as respire, perspire, inspire, aspire, and expire.