As a noun, it is the force of something pushing on a surface, or the stress you feel when you have a lot to do or big expectations. As a verb, it means to strongly push someone to do something.
From Latin *pressura* meaning 'a pressing', from *premere* 'to press'. It came into English through Old French, keeping both the physical and emotional sense of pushing.
The same idea explains air pressure and peer pressure—both are invisible forces pushing on you. Your body measures one with your ears and your mind measures the other with your feelings. Once you see pressure as a force, you can ask: where is this push really coming from?
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