Wiktionary
pin back
vb. (context transitive English) To keep at a distance
Usage examples of "pin back".
He also had to get his communicator pin back so he could contact Hunter.
He kept pushing the pin back and forth across the silk, careful not to let it slip through his fingers again.
And another thing-I bend both tips of the pin back whenever I install one.
He was bending to put the pin back when he saw movement-shadows-in the light coming from under one of the tall doors ahead.
When none came, he slipped the banshee pin back into its place and closed the case.