Smelly is a title which is unlocked by buying a Deathmatch title scroll for 600 Deathmatch points. It was previously a reward from the now-removed Crucible. This title was purchased with the trophy bones obtained from defeating other players. Unlike other titles, this was given to your opponent when they are killed and were not permanent.
This title changes according to the language of the server on which RuneScape is played, as shown below:
||Stinkender / Stinkende [Name]
||Le fétide / La fétide [Name]
||Fedido / Fedida [Name]