The Thracian word ars
Word ars
Meaning to flow
See also Armenian: aṙu ‘stream’
C. Luwian: a-ar-ši-ya- ‘to flow’
Synonyms e(i)b

Other words that might be of interest
achel- ‘water’, ala ‘current, stream’, alta ‘current, stream’, arma ‘swamp’, arta(s) ‘river’, iuras ‘water, river’, kaba(s) ‘bog, swamp’, kalsas ‘dry, dried up’, mar ‘water, river, bog’, ostas ‘river mouth’, pala ‘swamp’, sara ‘river’, sind(u)- ‘river’, strumon ‘river’, opa ‘water’, krisos ‘river name’