the space above the earth that you can see when you look up, where clouds and the sun, moon and stars appear
What's that in the sky?
The sky suddenly went dark and it started to rain.
the night sky
a cloudless sky
a land of blue skies and sunshine
The skies above London were ablaze with a spectacular firework display.
there is no limit to what sb can achieve, earn, do, etc.
With a talent like his, the sky's the limit.
an event that sb talks about that seems very unlikely to happen
This talk of moving to Australia is all just pie in the sky.
to praise sb/sth a lot
to hit a ball very high into the air
She skied her tee shot.