Whilst this answer/post, unfortunately, does not provide the word itself, it points one in the right direction to locate it.
From my comment above:
The verb was mentioned, by Stephen Fry, in an episode of QI (a quiz show on BBC) prior to 2009. I distinctly remember the episode, and I, then, quizzed my French colleagues at work, about the word, the following day - suffice to say that they had never heard of the verb before.
Much to my regret, I can not remember the verb exactly but it was similar in sound and spelling to prommener (to walk) or pommier (apple tree). I have searched for the episode (either transcript or video clip) many times since then, but have, unfortunately, been unable to find it.
It was a single word verb though, and not a phrase.