if you are en route to a place, you are on your way there.

They were en route to Geneva when they heard the news. (usually + to)

• when was a twinkle in father's eye
• when was a twinkle in their father's eye
• when your ship comes in
• where is coming from
• where someone is coming from
• Where's the beef?
• Where there's a will there's a way!
• Where there's muck, there's brass.
• where there's smoke, there's fire
• whet appetite
• whether by accident or design
• whether or not
• whet someone's appetite
• which way the wind is blowing
• while away
• while away something
• while back is turned
• while someone's back is turned
• While the cat's away .
• While the cat's away the mice will play.
• while the going is good
• whip into shape
• whipping boy
• whip-round
• whip someone into shape