Ⅰ.
sign on the dotted line
► LAW to sign a legal agreement: »
A financial adviser can suggest questions you should ask before signing on the dotted line.
Main Entry: ↑dotted line
Ⅱ.
sign on the dotted line
► to agree to do something, especially by signing an agreement: »
Many people sign on the dotted line without reading their policy documents.
Main Entry: ↑sign
Financial and business terms. 2012.