a strong, clear and definite change in a situation 大转变；巨变 It was one of those momentous events that cause a sea change in public attitudes. 这是那些导致公众态度大转变的重大事件之一。 Television has undergone a sea change in the last two years. 过去两年里电视发生了巨大的变化。
Word Originfrom Shakespeare's Tempest (i. ii. 403).