What is Counter-security?

Legal Definition
Security given to one who has become security for another, the condition of which is, that if the one who first became surety shall be damnified, the one who gives the counter security will indemnity him.
-- Bouviers Law Dictionary
Legal Definition
A security given to one who has entered into a bond or become surety for another; a countervailing bond of indemnity.
-- Black's Law Dictionary
Legal Definition
Indemnification of a surety.
-- Ballentine's Law Dictionary