'Defendant' is Latin for 'one who strikes away' — from *fendere (to hit), kin to 'offend' and 'fence.'
A person or entity accused in a court of law; the party against whom a legal action is brought.
From Old French 'defendant,' present participle of 'defendre' (to defend, to forbid, to protect), from Latin 'dēfendere' (to ward off, to protect, to repel), from 'dē-' (from, away) + 'fendere' (to strike, to hit), an unattested verb reconstructed from compounds like 'offendere' (to strike against) and 'dēfendere.' The PIE root is *gʷhen- (to strike). A defendant is etymologically someone who 'strikes away' an accusation — who wards off the legal blow being aimed at them. Key roots: dēfendere (Latin: "to ward off, to protect"), *fendere (Latin: "to strike (reconstructed)"), *gʷhen- (Proto-Indo-European: "to strike, to kill
The words 'defend,' 'offend,' and 'fence' all come from the same Latin root *fendere (to strike). To defend is to 'strike away' an attack; to offend is to 'strike against' someone. A fence was originally a shortened form of 'defence' — a barrier that 'strikes away' intruders. So a defendant behind a fence is doubly protected by the same root.