maštati

1. to daydream; to fantasize
   Umesto da uči, on sedi i mašta. — Instead of studying, he sits there daydreaming.
2. (o + loc.) to dream of; to dream about
   Oduvek je maštala o kući na moru. — She has always dreamed of a house by the sea.
   Maštam o tome da putujem po svetu. — I dream of traveling around the world.

The object of the dream usually takes o + locative: maštati o nečemu.