1 [C] either of the firm pink parts of your mouth that hold your teeth 齿龈；牙龈 ☞picture at body 见body插图

2 [U] a substance that you use to stick things together (especially pieces of paper) 胶（用来黏东西，尤其是纸张）

3 = CHEWING GUM ☞ Look at bubblegum. 参看bubblegum。