What do you call the cloud of gas and dust from which new stars condense?
The gases and dust from which stars condense are called cosmic dust or particles.
A Nebula is a massive cloud of dust, gas and debris (sometimes left over from a star that has died in a supernova explosion) drifting in interstellar space. It is from these nebula that stars are thought to form. Once the stars "come to life" this is thought to kick start the formation of other stars and planets from the remaining gas, dust, rock, metal in the dust cloud.