yam, “seas,” strong’s H3220

The first occurrence.

And God called the dry land Earth; and the gathering together of the waters He called Seas: and God saw that it was good. Gen 1:10

The primitive root.

Strong’s H3220  ים yam, a concrete noun meaning, “seas;” from an unnamed, unused primitive root meaning, “to roar.” The pictographs for the noun are yud + mem.

yud י = the closed hand, thus work, throw, worship
mem מ ם  = the water, thus chaos, mighty, blood

The story: Working (yud) water (mem), as the water of the sea is always moving.

THE ANCIENT HEBREW LEXICON | INDEX OF HEBREW ROOTS