get under

get under (something)

Literally, to move or position oneself underneath or below something. The kids got under the covers, and I started reading their bedtime story. Ugh, the mouse got under the bookshelf somehow—we'll never catch him now!
See also: get
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

get under something

to get beneath something. The cat came in and got under the sofa where she couldn't be seen. Why don't you get under the table where Billy won't find you?
See also: get
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
See also:
References in periodicals archive ?
With less new aircraft, and with some wonderful oldies flying too, after the first day, the actual air display program did not actually get under way until 1pm, more like Farnborough, and starting with the helicopters.