A person who careers; someone who moves rapidly or who is actively pursuing a professional career path.
From career + -er (agent noun suffix). A rarely used term created by analogy with other agent nouns, though 'careerist' became more common for the professional sense.
While 'careerer' is technically correct English, it never caught on because 'careerist' sounded better—this shows how language competition works, where one term wins out not on grammatical merit but on phonetic appeal.
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