SUSI

susi
key

walang susi ang bibig
"lips without a key or lock"
cannot keep a secret

Hanapin mo ang susi.
Look for the key.

susian
lock

Susian mo ang kuwarto.
Lock the room with a key.

Sinusian ko ang pinto.
I locked the door with a key

masusi
detailed, minute

masusing pagsusuri
detailed analysis