intervene, step in (an argument), edge in (a market)

Kyūjitai form of 貝殻: shell; seashell

nostalgia; longing for the old days

improvement, an action taken to improve / improvement, a spontaneous change for the better

(transitive) to improve, to make better / (intransitive) for something to improve on its own

remodel / reorganize, reshuffle

that which when read from start to end or end to start results in the same phrase; a palindrome. In Japanese, the sound unit is the mora, and voicing constraints are ignored.

a total eclipse; either solar or lunar

fast

high speed / a more rapid level of express train