coastline, shoreline / a railroad that follows a coastline

line / level / beam

(oceanography) tide level

always

coast; shore (the border between land and sea)

change, fluctuation

change, fluctuate

goblin, ghost; an apparition

change in society, climate, or condition, transformation, variety / variation / declension / (sumo) a step to one side during the tachiai, the initial charge at the start of a sumo match; a sidestep

to change, to vary