Coastal means beside or belonging to the coast. Coastal towns, coastal erosion, a coastal path.
Coastal erosion is not a fault to be fixed but a process, and holding one stretch in place usually starves the next along of sand — which is why managed retreat is now official policy in places. About forty per cent of the world's people live in coastal areas.
1adjectivecoastalBeside or belonging to the coast.
“Coastal towns are at risk of flooding when big storms hit.”
coastal is a quality of place.
Coast plus -al, from Latin costa, a rib or side. The coast is the side of the land.
Proto-Indo-European
*kost-
Latin
costa — rib; side, wall
Old French
coste — rib; side of an object; coast
Middle English
coste — rib; side of the body
English
coast
English, today
coastal
From coast + -al. From coast + -al. costal. coast comes from Middle English coste (“rib; side of the body”), from Old French coste (“rib; side of an object; coast”) (modern French côte (“rib; coast; hill, slope”)), from Latin costa (“rib; side, wall”). a doublet of costa. Compare typologically cape < caput, ness (akin to nose), нос (“nose; …; cape, promontory, foreland, gore”), ’рт, рт (“cape, promontory, headland”) < rъtъ (whence рот).
Etymology from Wiktionary, CC BY-SA