Someone who talks — but the word almost never stands alone. It comes with an idea of quantity or of style. Alone, "he's a talker" means he talks a lot, and often carries a hint that he does more talking than doing. With a word in front it describes how a person talks: a fast talker, a smooth talker, a great talker, a plain talker. Two of these have hardened into set phrases with their own meanings, and they are the ones you really need. A smooth talker uses charm and easy words to persuade people, usually for his own benefit — it is a warning. A fast talker is much the same, someone who talks so quickly and confidently that you agree before you have thought. There is also a common contrast in English: a talker versus a doer, meaning someone full of plans against someone who actually gets things done. Notice how odd this word is compared with worker or teacher, where the -er just names the job. Nobody's job is talker; the word is always a judgement.