Cameroon· hard· informal
mouiller la barbe de quelqu'un
“to wet someone's beard”
Meaning
To bribe someone
Explanation
In Central African French, wetting someone's beard means slipping them money to get a favour, the beard being a symbol of authority that needs 'refreshing' with cash.
Example
Si tu veux que ton dossier avance, il va falloir mouiller la barbe du fonctionnaire.
If you want your paperwork to move forward, you'll have to wet the official's beard.
Origin
Origin uncertain. The expression is widespread in Cameroon and the DRC, where 'la barbe' evokes the authority of an elder or official.
Where
Cameroon
DRC