Shotgun Clause

What Does Shotgun Clause Mean?
A buy-sell provision used by related parties in a business venture which gives an investor within the partnership the right to offer his/her portion to a partner at a specified price. If the partner does not buy the offered interest at this price, the partner must then sell his/her own interest to the offering party at the same specified price. 

Investopedia explains Shotgun Clause
The shotgun clause attempts to provide security to the partners of a venture by ensuring the offering of a fair price. Because the investor initially tendering the shares cannot be certain whether the shares will be purchased or rejected, the specified price must be carefully considered - after all, a rejection of the tendering creates an obligation for the offering party to buy the partner's portion at the same price he/she was originally willing to sell at.