|geography a tributary valley entering a main valley at a much higher level because of overdeepening of the main valley, esp by glacial erosion|
|hanging valley (hāng'ĭng) Pronunciation Key
A side valley that enters a main valley at an elevation high above the main valley floor. Hanging valleys are typically formed when the main valley has been widened and deepened by glacial erosion, leaving the side valley cut off abruptly from the main valley below. The steep drop from the hanging valley to the main valley floor usually creates cascading waterfalls.