0 to give a final message at the end of a letter or when communicating by radio, or at the end of a television or radio programme:
She signed off (her show) by wishing her listeners a Happy New Year.
1 to give a final message at the end of a letter or email or when communicating by radio:
There is no more news, so I'll sign off.
NOVÉ SLOVÁ
European
May 10, 2021
SLOVO DŇA
Shimmer
sign (sth) off