刻骨

ingrained / entrenched / deep-rooted

quarter (hour) / moment / to carve / to engrave / to cut / oppressive / classifier for short time intervals

bone

lit. carved in bones and engraved in the heart (idiom) / fig. etched in one's memory / unforgettable

lit. etched into one's heart and bones (idiom) / fig. etched in one's memory; remembered with gratitude as long as one lives

engraved in one's heart and carved in one's bones (idiom); to remember a benefactor as long as one lives / undying gratitude

deep-seated lovesickness (idiom)