Quarterly

wiktionary

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quarter +‎  -ly

etymonline

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quarterly (adv.)

early 15c., quarterli, "four times a year, once a quarter," from quarter (n.1) + -ly (2). As an adjective from mid-15c., "occupying alternate quarters" (of a coat of arms), with -ly (1). As a noun, "a quarterly publication," from 1830, from the adjective. Earlier the adverb was used in a now-obsolete sense of "into quarters" (c. 1400).