Verses with the word calm in the Old Testament (3 verses):

Psalms 107:29
He maketh the storm a calm, so that the waves thereof are still.

Jonah 1:11
Then said they unto him, What shall we do unto thee, that the sea may be calm unto us? for the sea wrought, and was tempestuous.

Jonah 1:12
And he said unto them, Take me up, and cast me forth into the sea; so shall the sea be calm unto you: for I know that for my sake this great tempest is upon you.