πετρώδη [4 verses](adj pl neut acc) "Stony places" is from petrôdês, which is an adjective meaning "like rock" ""rocky," and "stony."  - Stony places" is from an adjective that means "rocklike" and "stony." It is used as a noun, being introduced by an article ("the"), so "the stoniness" or "the rockiness." The metaphor here is a hardness of mind.