The meaning of かたに in かたに預ける


I heard an expression:

> その◯◯が二両の **かたに** 預けてあるのは、彼は知りません。

The intended meaning was "he did not know that ◯◯ has been pawned for 2 ryō".
Not a pawn-shop, but given as a collateral to a person who lends money.

I searched all dictionaries I had in hand specifically for a meaning that
would fit the case and could not find any.

Did I miss anything in dictionaries or did I just mishear? Is there such a
phrase? If so, what would be the etymology, ie. which one of 方, 形, 片, ...
would it be and why?




It is `形` (mortgage).

> ２ （形）証拠に残すしるし。保証のしるし。抵当。「カメラを借金の―に置く」

<http://dictionary.goo.ne.jp/jn/41603/meaning/m0u/%E5%BD%A2/>

