This is the 8127th most frequent French word.
tunisien
Tunisien: Tunisian (relating to Tunisia or its people).
Here, 'tunisien' is used as an adjective describing nationality.
Il est tunisien et parle couramment français.
He is Tunisian and speaks French fluently.
In this sentence, 'Tunisien' functions as a noun referring to a person from Tunisia.
J'ai rencontré un Tunisien au marché hier.
I met a Tunisian at the market yesterday.
Here, 'tunisienne' is used as an adjective specifying a type of cuisine related to Tunisia.