Cameroon· easy· informal
gâter le nom de quelqu'un
“to spoil someone's name”
Meaning
To damage someone's reputation
Explanation
In Cameroon and across Central Africa, your 'nom' is your honour and public standing. To 'gâter' it means to tarnish or ruin it through scandal or bad behaviour.
Example
Il a triché à l'examen et il a gâté le nom de toute la famille.
He cheated on the exam and ruined the whole family's name.
Origin
Origin uncertain. In many Central African cultures, a family name carries collective honour, so 'spoiling' it affects everyone who shares it. The expression is common in Cameroon and neighbouring countries.
Where
Cameroon
DRC
Congo