sukkari
Describes something that has completely and thoroughly changed or occurred — forgetting entirely, healing fully, or a season fully arriving.
💡Forgetting an appointment — 'I sukkari forgot about our meeting!'
すっかり秋になった。
It has sukkari completely become autumn.
I ___ forgot to call you back — I'm so sorry!
○○電話し忘れてしまった。ごめんなさい！