Definitions of "painterly" through the ages. Consensus? Hmm. Most of them mention color vs. line. I prefer something a bit more encompassing.
My fav def so far, from Dan Twitchell:
A work of art done in a manner that embraces, shows, and celebrates the medium it's created in (be it oil paint, pastels, watercolor, graphite, charcoal, ink, etc.), rather than tries to hide the act of creation.