Illyrian was spoken by the Illyrians, an ancient tribe located around the present-day Balkan. It is an Indo-European language. See below a glossary/vocabulary with Illyrian words & meanings.
Glossary:

Illyrian Indo-European
alt- (a stream) (in Altus – a hydronym)
barba- (a swamp) (in Metubarbis – a toponym) Albanian berrak (swampy soil), Sanskrit barburam (water), Greek borboros (slime)
bra’ (brother! (vocative)) *bhra’te’r ‘a brother’
brisa (husks of grapes)
cleves- (famous) (in Vesclevesis – a personal name) *kleu- (to hear, to listen), Latin clarus (famous), Greek kleos (fame)
lugo- (a pool)
mag- (great) *meg- (great)
metu- (between) (in Metubarbis – a toponym) *medyo- (medium, between)
oseriates (lakes) Slavic *ozero (a lake), Lithuanian ez’eras (a lake)
plo- (strong, powerful) *plu- (numerous)?
rinos (clouds)
sybina (a spear)
tertigio (a merchant) Slavic *türgü (a market), Lithuanian tirgus, Albanian trege” (a market)
teuta- (people, a tribe) “European” *teutá- (people, a tribe), Oscan touta (a tribe), Gaulish teuto- (people)
ves- (kind, good) (in Vesclevesis – a personal name) *wesu- (good, kind)