yield something ↔ up phrasal verb formal ( see also ↑ yield )
1 . to show or produce something that was hidden or difficult to find, or that people did not know about SYN throw up :
New research has yielded up some surprising discoveries.
2 . British English to give something that belongs to you to someone else, because you are forced to SYN surrender :
He would never yield up the castle to the English.