back down — 물러서다(굽히다)→ He refused to back down.back out of (contract) — (계약을) 철회하다→ He backed out of the deal at the last minute.back out — 빠지다(하기로 한 걸 안 하다)→ We were going to start a business together, but he backed out.back up (claim) — (주장을) 뒷받침하다→ Can you back that up with evidence?back up (someone) — (누군가를) 지원하다→ I'll back you up.back up (data) — (데이터를) 백업하다→ Don't forget to back up your fi..