The term ''big cat'' is typically used to refer to any of the five living members of the genus Panthera, namely tiger, lion, jaguar, leopard and snow leopard. Except the snow leopard, these species are able to roar. A more liberal and expansive definition of the term includes species outside of Panthera including the cougar, clouded leopard, Sunda clouded leopard and cheetah, although these added species also do not roar.

Can we conclude that is lion a member of the cat family?
yes