눈치 means
1. tact; sense; quick[ready] wit. used with 있다 없다 빠르다 느리다 채다
2. one's frame of mind; (facial) expression; a sign; a hint; an indication. used with 보다 보이다 살피다 주다
눈치 있다 have sense
눈치 없다 have no sense
눈치 보다 try to read one´s mind[face]
눈치만 보다 only try to read one´s mind[face], feel diffident
눈치가 빠르다
be quick-witted/be ready-witted/have quick wits/be tactful[sensible]
눈치를 살피다
study the pleasure of 《a person》/read[study] 《another's》 face[countenance].
눈치를 보이다
express 《one's emotions》 by outward signs/betray 《one's mind》 in one's look.
눈치채다
become aware of [that]; be conscious [suspicious] of; suspect; sense; get wind [scent] of; smell; take hint of; get wise to.