1. To continue to be physically next to or close to one another. We should remain together—these woods would be a bad place to get lost! These two items are a set, so they should remain together throughout the exhibition.
2. To continue to be in close contact or association. The group of friends remained together for years after they finished high school. The director and actor remained together for a number of different films.
3. To continue to be in a romantic relationship with one another. They fight and argue so much that it's hard to see why they even remain together. I know my dad and mom remained together out of a misplaced sense of propriety and duty, not because they loved each other.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
to stay close together; to stay in association. We will have to remain together while we are on this tour. It is very easy to get lost in this town. The two boys remained together throughout college.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.