Literally 'thicket you cannot know', referring to a dense, confusing thicket or a place where one easily gets lost. Often used metaphorically for a complex, bewildering situation.
This forest is like a labyrinth.
The paperwork at the government office feels like a maze.
Standard kanji spelling. 藪 is a non-jōyō kanji, so kana spelling is also common.
Common mixed spelling when 藪 is written in kana.
The figurative sense derives from 八幡の藪知らず, the name of a famously forbidden thicket at Ichikawa in Chiba, which became a byword for a place one enters but cannot find one’s way out of.