perturbation

1. N-VAR A perturbation is a small change in the movement, quality, or behaviour of something, especially an unusual change. (尤指不尋常的)小變化[技術]

...perturbations in Jupiter's gravitational field. ...木星重力場的微小變化。

2. N-UNCOUNT Perturbation is worry caused by some event. 憂慮; 不安[正式]

This message caused perturbation in the Middle East Headquarters. 這個消息在中東總部引起了不安。