It's a heteronym, see[1]. And etymologically they seem to be related, the sense "quit" dating back to the 14th century while the sense "sign again" a more recen

It's a heteronym, see[1]. And etymologically they seem to be related, the sense "quit" dating back to the 14th century while the sense "sign again" a more recent addition, 19th century [2] [1] https://en.wiktionary.org/wiki/heteronym https://en.wiktionary.org/wiki/heteronym [2] https://www.merriam-webster.com/dictionary/resign https://www.merriam-webster.com/dictionary/resign