狭窄 (xiá zhǎi) is a formal, written adjective for 'narrow' in both physical space and abstract scope (e.g., knowledge, mind). It is more literary than 窄 (zhǎi), which is the everyday spoken word for physical narrowness. 狭隘 (xiá ài) is its near-synonym but leans toward narrow-mindedness or provincial thinking, while 狭小 (xiá xiǎo) emphasizes cramped smallness.