[shī xiào]
(失去效力) lose efficacy; lose effectiveness; cease to be effective
									
										The medicine no longer has any effect.
										这药已失效了。
									
									(无效) (of a treaty, an agreement, etc.) be no longer in force; become invalid
									
										voidance; voidness of treaties
										条约的失效
									
									
									
										an invalid cheque
										一张失效的支票
									
									
									
										automatically cease to be in force
										自动失效
									
									
									
										This certificate is invalid.
										这张证明已失效。