Rainproof vs Watertight - What's the difference?

As adjectives the difference between rainproof and watertight

is that rainproof is (of external clothing) waterproof while watertight is so tightly made that water cannot enter or escape.

is to make rainproof.

(en adjective)

(of external clothing) waterproof

(en verb)

To make rainproof.

(en adjective)

So tightly made that water cannot enter or escape.

So devised or planned as to be impossible to defeat, evade or nullify.

a watertight''' contract; a '''watertight regulation.

* watertight alibi * watertightness