sign(sth)off
—phrasal verbwithsignverbuk/saɪn/us/saɪn/
to give afinalmessageat the end of aletteror whencommunicatingbyradio, or at the end of atelevisionorradioprogramme
结束（写信、广播或电视节目）
Shesignedoff (her show) bywishingherlistenersa Happy New Year.她在结束播音时祝听众新年快乐。