This is the 3998th most frequent French word.
burundais
Burundais: Relating to Burundi or its people; Burundian.
Here, 'Burundais' functions as a noun referring to a person from Burundi.
Un Burundais est venu visiter notre école aujourd'hui.
A Burundian came to visit our school today.
Here, 'burundais' is used as an adjective modifying 'étudiant,' indicating that the student is from Burundi.
Je connais un étudiant burundais.
I know a Burundian student.
In this sentence, 'burundaises' is used as an adjective, plural and feminine, to describe 'traditions,' indicating attributes related to Burundi.