When you act passively, you don't put up any resistance — in fact, you hardly respond at all. Some people take charge during group projects and others passively accept whatever role is assigned to them.
Doing something passively means giving in to someone else's actions or demands without any real response at all. It's easy for your soccer team to win against the opposition when they hardly put up a fight, passively accepting defeat as you score goal after goal. Another way to use this adverb is to mean "using sunlight or the earth's heat as an energy source." Passively heating your new home will save so much money on energy bills!