Newbie

wiktionary

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Origin uncertain: perhaps an alteration of newie with intrusive b (compare freebie), possibly a blend of newborn +‎ baby, or perhaps a shortening of new boy or new beginner.

etymonline

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newbie (n.)

"newcomer, new person to an existing situation," by 1969, from new with diminutive or derogatory suffix. Perhaps originally U.S. military slang. Compare noob. Middle English had newing "a new thing" (early 15c.); new was used as a noun meaning "naval cadet during first training on a ship" (1909); and newie "new thing" is recorded from 1946.