expression, godan verb (-bu)
build a hermitage; retreat from the world
Literary set phrase for building a small, simple dwelling to live in seclusion, often with Buddhist or poetic overtones.
彼は俗世を離れ、山奥に庵を結んだ。
He left the secular world and built a hermitage deep in the mountains.
隠遁する means 'to seclude oneself' or 'retire from the world' in general, while 庵を結ぶ specifically refers to the act of building a physical hermitage as part of that retreat.
The phrase combines 庵 (hermitage, small hut) with 結ぶ (to tie, build), literally 'to tie/build a hermitage'. The exact historical origin is uncertain, but it is a classical expression associated with reclusive life.