To see something and then catch it.
This can make people think of hunting or trying to get something that is hard to get.
Examples:
I seecatch a butterfly in the garden.
She seecatches a fish in the river.
The cat seecatches a mouse in the house.
I seecatch a cold every winter.
He seecatches a shooting star in the sky.
We seecatch fireflies in the dark.