Building

google

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Old English byldan, from bold, botl ‘dwelling’, of Germanic origin; related to bower1.

wiktionary

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From Middle English bildyng, buildyng, buyldyng, byldyng, bulding, beldyng, equivalent to build +‎ -ing.

See build

etymonline

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building (n.)

c. 1300, "a structure;" late 14c., "act or process of constructing;" verbal noun from build (v.). Building-block is 1846 as "one of a set of children's play blocks;" 1849 as "temporary support on which a ship's keel rests while the ship is being constructed;" 1856 as "cinder-block, concrete block, artificial stone block used in building construction." Figurative sense "basic unit from which something is constructed" is by 1955.