Cosign has 4 different meanings across 1 category:
Verb
Noun
1
The promotion of one musical artist (usually less successful) by another.
Verb
1
sign jointly
"Husband and wife co-signed the lease"
2
sign and endorse (another person's signature), as for a loan
3
To sign a document jointly with another person, sometimes as an endorsement.
Broader Terms (hypernyms)