지극해요 · 지극했어요 · 지극한 (+noun)
utmost, extreme, devoted (care, love, sincerity)
Example
어머니의 지극한 사랑 덕분에 병이 나았어요.
Thanks to my mother's devoted love, I recovered from my illness.
Word parts
지 utmost+극 extreme
Literally 'reaching the extreme'.
Good to know
The adverb 지극히 'extremely' is common: 지극히 정상적인 반응이에요.