bound to do
bound to (be or do something)
Apt or likely to do something. We all thought that Doug was bound to be an artist, so we were very surprised when he became a trader on Wall Street. A: "Do you think it will rain today?" B: "It hasn't rained for weeks, so it's bound to."
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
bound to do something
certain to do something; destined to do something. Jill's bound to do a good job. We are bound to tell the truth.
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.