Noah Webster's Dictionary (n.) A secluded and narrow valley; a dale; a depression between hills.

Multi-Version Concordance Glen (1 Occurrence) Zechariah 1:8 "I had a vision in the night, and behold, a man riding on a red horse, and he stood among the myrtle trees that were in a ravine; and behind him there were red, brown, and white horses. (See RSV)