supstanca

1. substance
   Ova supstanca je veoma otrovna. — This substance is very poisonous.
   Policija je u stanu pronašla zabranjene supstance. — The police found illegal substances in the apartment.
2. formal substance; essence
   Njegov govor je bio lep, ali bez supstance. — His speech was nice, but it lacked substance.

For the meaning “essence”, “suština” is more common.