The area by and around the sea; including the beach, promenade or cliffs
This summer, I'm going to the seaside at Weymouth - I'm very excited about it!
1907, John A. Glover-Kind, I Do Like To be Beside the Seaside (song)
I do like to be beside the seaside! Oh, I do like to be beside the sea! I do like to stroll along the prom, prom, prom, While the brass bands play Tiddely-om-pom-pom!