train as

train as (something)

1. To become educated in order to work in a certain professional role. I originally trained as a doctor, but I ended up teaching English in Japan. My brother has been training as a financial analyst.
2. To educate, coach, or prepare someone or an animal to work in some specific role. In this usage, a noun or pronoun is used between "train" and "as." We'd like to start training you as our new sales manager. These puppies are being trained as a guide dogs, so please don't pet them or feed them anything.
See also: train
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

train (someone or an animal) as something

to educate someone or an animal to serve in a particular way. We trained him as a first-rate mechanic. I trained my cocker spaniel as a moderately effective watchdog.
See also: train
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
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References in classic literature ?
Then they came upon vast tracts extending to the horizon, with jungles inhabited by snakes and tigers, which fled at the noise of the train; succeeded by forests penetrated by the railway, and still haunted by elephants which, with pensive eyes, gazed at the train as it passed.
He turned and looked down the train as we alighted.