noun, noun which may take the genitive case particle 'no'
with all one's might; with one's whole body and soul
Used to describe putting all of one's physical or mental energy into an action. Often appears as 渾身の〜 (e.g., 渾身の力, 渾身の一撃).
He pushed the rock with all his might.
This is a work the author poured his heart and soul into.
He knocked his opponent down with an all-out blow.
I threw the ball with everything I had.
全身全霊 stresses devoting one's entire body and spirit (often to a cause or duty), whereas 渾身 usually describes a single burst of maximal effort in one action.
精一杯 is a softer, everyday way to say 'as much as one can', while 渾身 has a heavier, more forceful and literary tone.
渾身 (whole-body effort in one action) is easily confused by sound with 献身 (けんしん, selfless devotion or sacrifice for others), but their meanings are unrelated.
Standard kanji spelling.
Mixed kanji-kana spelling, sometimes used for readability.
From 渾 (all, whole) and 身 (body). The exact historical derivation is uncertain, but the compound literally means 'whole body' and is used figuratively for total effort.