Kyūjitai form of 海戦 (“naval battle”)

to study / to learn

the past / ancient times

(not of a person) old, aged, antiquated

old

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

a sea, an ocean / a lake / (figuratively) an object covering over a large area, as in 血の海 (chi no umi, “pool of blood”) or 火の海 (hi no umi, “sea of fire”)

history / the study of history