seashore: the band of land running along the sea, whether as a place to settle, a coastal region of a country, or a beach where ships put in
This is a rare word, used only seven times, and it never stands alone: it is always the shore of something. Six times it is the shore of the sea, and once, in Genesis 49:13, it is a shore for ships. What it pictures is the strip of ground beside the water, seen from the land looking out.
When the writers survey the promised land, it names a region. Deuteronomy 1:7 and Joshua 9:1 both run through the country's zones, the hill country, the lowland, the south, and then the seacoast, so the word marks off the whole western strip beside the Mediterranean rather than the narrow line the waves reach. Prophecy against Philistia uses it the same way in Jeremiah 47:7 and Ezekiel 25:16, where the seacoast is a territory under judgment.
In poetry it becomes a place a people lives. Zebulun settles at the shore of the seas and Asher stays by the coast, which is worth noticing in a nation whose story runs mostly inland. Genesis 49:13 then presses further: Zebulun will be a shore for ships, a beach boats can put in at, which most English Bibles render "a haven for ships."
Hebrew has other ways to speak of a seaside, and the differences matter. The commonest is a word for a lip or edge (שָׂפָה), the sea's lip. Another word (אִי) reaches past the near shore to the far coastlands and the peoples living on them. This word stays close in: the ground where the water stops.