self-sealing
/ˌselfˈsiːlɪŋ/adjective
1- sealing itself without the usual process or procedure, in particular自动封闭的, 尤指：
1.1
- (of a pneumatic tyre, fuel tank, etc.) able to seal small punctures automatically（充气轮胎、油箱等）自动封住小穿孔的。
1.2
- (of an envelope) self-adhesive（信封）自粘的。