Collins Chinese Dictionary Plus (3rd edition), 2011:
不但 bùdàn 连
not only
- 这(這)辆(輛)车(車)的设(設)计(計)不但美观(觀),而且实(實)用。 Zhè liàng chē de shèjì bùdàn měiguān, érqiě shíyòng. The design of this car is not only beautiful, it's also practical.