A tsunami in a dream usually represents emotion so large and sudden that it threatens to sweep away everything in its path, often something you didn't see building until it was already close. It can surface during a crisis that feels bigger than your capacity to manage, leaving you searching for higher ground rather than a way to stop it.
The first sign hath pre-eminence in signification, when there be two signs have to do with the thing. - William Lilly (1602.-1681.)