self-protection; self-preservation
Often implies protecting one's own position, interests, or reputation, sometimes with a negative nuance of selfishness or avoiding responsibility. Common in phrases like 保身に走る (to act out of self-preservation) and 保身のために (for self-protection).
He hid the truth for self-preservation.
The politician acted out of self-protection and did not take responsibility.
Compound of 保 (preserve, protect) and 身 (body, oneself). The exact historical derivation is uncertain, but the meaning has been stable as 'protecting oneself' in modern Japanese.