when you drop your cell phone in the rode and your about to get ran over by a car and you really say o shit but the way you say it makes your friend think you said ooosh.
"Ooossshh" is a word made popular by Keith Lemon, but in fact the word has been around since time immemorial. It describes the effect of great excitement and is the sound emitted when pressure is released when opening a can of shaken lager. It can also be the description of other activities.
I was rigourously sucking the nipples of my heavily pregnant girlfriend when she ooossshhhed all over my moustache.
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.