Belgium· informal
dikkenek
Meaning
a boastful show-off
Elsewhere
vantard
Explanation
A Belgian show-off is a dikkenek, a thick neck, borrowed from Dutch. France would say vantard.
Example
Arrête de jouer les dikkeneks, tout le monde sait déjà que t’as gagné.
Stop being such a show-off, everyone already knows you won.
Origin
From Dutch dikkenek, a compound of dik (fat, thick) and nek (neck).
Source