Sign on has 3 different meanings across 1 category:
Verb
Noun
1
The time of day when a radio or television station begins broadcasting, usually after being off the air for several hours.
Verb
1
engage by written agreement
"They signed two new pitchers for the next season"
2
To join something, after signing.
Related Terms
Broader Terms (hypernyms)
Narrower Terms (hyponyms)