Expansion

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early 17th century: from late Latin expansio(n- ), from Latin expandere (see expand).

wiktionary

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From French expansion, from Latin expānsiō.

etymonline

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expansion (n.)

1610s, "anything spread out;" 1640s, "act of expanding," from French expansion, from Late Latin expansionem (nominative expansio) "a spreading out," noun of action from past-participle stem of Latin expandere "to spread out, unfold, expand," from ex "out" (see ex-) + pandere "to spread, stretch" (from nasalized form of PIE root *pete- "to spread").