flight·y
adjective/ˈflaɪti/
/ˈflaɪti/
(old-fashioned, informal)- somebody who is flighty cannot be relied on because they often change their activities, ideas or partners and do not treat them seriously
反复无常的人不值得信赖，因为他们经常改变自己的活动、想法或合作伙伴，并且不认真对待他们 Word Originmid 16th cent.: from flight + -y.