Niche: a shallow recess, nook, cranny, slot, slit, hollow, cavity, cubbyhole, pigeonhole... There are other words but these are the most succinct for my example of the confined, claustrophobic space the word evokes.

​It also represents an anti-creative state of mind that limits the chance for out of the box discoveries that produce the giant ah-ha moments of forward movement in life and in history.