From Latin 'excludere' (to shut out) — exclusion always implies a boundary and someone on the wrong side of it.
To deny access to; to shut out; to leave out or omit from a group, set, or consideration.
From Latin 'exclūdere' (to shut out, to drive out by closing), composed of 'ex-' (out, from, away from) + 'claudere' (to shut, to close, to bolt), from PIE *klāu- (hook, peg, nail — the device for fastening). 'Claudere' generated a remarkable family: 'include' (shut in), 'conclude' (shut completely, bring to a close), 'preclude' (shut off beforehand), 'occlude' (shut against), 'recluse' (one who shuts away), 'sluice' (a controlled gate), 'cloister' (a locked enclosure), 'clause' (a grammatical unit that closes), and 'closet.' The PIE root *klāu- appears in Greek 'kleís' (key), giving
The word 'exclusive' has undergone a remarkable status reversal. Originally negative — 'exclusion' meant being shut out — the adjective 'exclusive' became a mark of prestige. An 'exclusive club' or 'exclusive neighbourhood' derives its desirability precisely from shutting people out. Luxury marketing has turned a word about doors closing into one about privilege.