Echelon

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late 18th century (in echelon (sense 2 of the noun)): from French échelon, from échelle ‘ladder’, from Latin scala .

wiktionary

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Borrowed from French échelon(“rung; echelon”), from échelle(“ladder”) + -on(“suffix forming diminutives”). Échelle is derived from Latin scāla(“ladder”), from scandō(“to ascend, climb”), from Proto-Indo-European *skend-(“to jump”).

etymonline

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echelon (n.)

1796, echellon, "step-like arrangement of troops," from French échelon "level, echelon," literally "rung of a ladder," from Old French eschelon, from eschiele "ladder," from Late Latin scala "stair, slope," from Latin scalae (plural) "ladder, steps," from PIE *skand- "to spring, leap" (see scan (v.)). Sense of "level, subdivision" is from World War I.