A little more in depth...
Feeble - frontwheel on ledge, back hanging off grinding
Smith - backwheel on ledge with front hanging off
Railslide/boarslide - grinding the rail, sort of in the feeble position
Lipslide - jumping over the rail and grinding, sort of like the smith position
Salad - deck is on ledge in the feeble position but the front end is lifted up
Overcrook - front end is on ledge, in a crooked position when the back end is in the air
Noseblunt - Front end is on the ledge, back end is in the air, you are auctually griding with the front of the deck behind the fork and "looking off the coping"(not to be confused with a nosegrind)
5050 - Grinding on the whole edge of the deck
Nosegrind - Grinding on the front end of the deck deck next to the folding mech with the backwheel in the air
5-0/Pegless icepick - Grinding on the back edge of the deck (dropouts) with the front end in the air
Then theres fakie grinds, peg grinds if you have them on, and probably some weird stuff im forgetting that doesn't really have a name.
Jumping on a scooter? I usually just call it jumping.