高 (high) +
攀 (to climb) — vividly literal: 'climb upward.' The phrase
高攀不起 'can't climb that high' is one of Chinese's most polite (and sarcastically biting) refusals — it pretends you're too lowly to deserve the other person, but in tone often means 'I don't want anything to do with you.' Listen for it in romance dramas when one family looks down on another.