From Longman Dictionary of Contemporary Englishsign something ↔ away phrasal verbGIVEto sign a document that gives your property or legal rights to someone else She had signed away all claims to the house. I felt as if I was signing away my life. → sign→ See Verb table
Examples from the Corpus
sign away• But unlike John Major's predecessor, he shows no sign of fading away.• There are so many horror stories about ESOPs that many men would just prefer to sign their money away.• You pay £25 and sign your life away, agreeing no one else is responsible, especially not Bungy Jump International.• But it is showing signs of turning away from extreme neutrality. 