尽じん瘁すい

Meanings

1

noun, noun or participle which takes 'suru', intransitive verb

devoting oneself entirely; giving one's all

Rare literary word for exhausting oneself in service or effort. Often used in formal or historical contexts.

瘁take sick, fatigue

尽じん力りょく
Common word for making efforts or contributing; 尽瘁 is much rarer and implies exhaustion or total dedication.
粉ふん骨こつ砕さい身しん
Four-character compound meaning 'sparing no effort'; 尽瘁 is a single kanji compound with a similar nuance but more literary.

Compound of 尽 (exhaust) and 瘁 (overwork, ailment). The exact historical derivation is uncertain; it is a literary Sino-Japanese word.