to do something secretly without their knowledge
hacer algo secretamente sin su conocimiento (hacer algo secretamente sin su conocimiento)
"She was talking about me behind my back."
"Ella estaba hablando de mí detrás de mi espalda." (Ella estaba hablando de mí **detrás de mi espalda**.)
to adapt to difficulties and keep going
to stop paying attention and mentally drift away
to go to ground; to take cover or hide
to stop fighting and surrender
to dismiss something by treating it as a joke
To go beyond acceptable or proper boundaries.