The opposite of being still could be moving, or restless, wiggly, jumpy.
The opposite of still occurring (at this time) would be "no longer" occurring.
WALK
No, extant means still existing.
The opposite is a calm sea. Other words could be placid, moderate, gentle, tranquil, etc.
A person of either sex, who is under 18 and still unmarried.
There is no opposite. Risotto is at its simplest a dish of rice cooked with a stock until the rice is cooked but the dish is still very liquid, the rice not having taken up all the stock.
The opposite of "be still" is "move."
The opposite of lurk is introduce. The opposite of be still is to be moving. They are two completely different words.
It is still Hot.
Be still
The opposite of still water is gaseous or "sparkling" water. Technically though there is no "still" water if the opposite is gaseous water. The reason for this is that most most water known as "still" water contains quite alot of dissolved gas. Put simply the opposite of still water sparkling, that it's gaseous contain can be seen and/or felt as sensation in the mouth.
WALK
stand still
No, extant means still existing.
The opposite of fast wind would be calm or still air.
still zero
Opposites for still are moving active noisy turbulent stir up no longer
The opposite of odd is even. If you divide a even or odd number with odd, you will still get a fraction, or a romander.