To me, a grower is often a "difficult" album, perhaps not very melodic, but having other qualities that I pick up on after further spins. It can also extend to things I may have heard on the radio, or in a shop, anything really. For example when Nirvana broke big with "Nevermind", I'd only heard the stuff in CD shops and thought it was just a bloody racket, but then a cousin lent me a copy of "Incesticide", and I was sold after the opener, "Dive."

A classic "grower" name would be someone like David Crosby. His songs don't exactly leap at you, but work their way into your mind slowly. They grow on you.
