Fights or battles with imaginary enemies or shadows.
Sciamachies are usually seen as playful or not serious.
Examples:
He pretends to have sciamachies with the monsters under his bed.
The children had sciamachies with their own reflections in the pond.
She enjoys sciamachies with the wind in the garden.
The cat's sciamachies with its tail are always funny to watch.
In her dreams, she has sciamachies with dragons and fairies.
The sciamachies of the little boy always make his parents smile.