Native speaker
In Emirati Arabic, “Eighty (80)” is ثمانين (thmaaneen).
ثمانين
Eighty (80)
It's in the phrasebook under Numbers, prices & money, with 36 more like it.
sab'een
tis'een
siteen
imya
khamseen
alif
Source: DLIFLC Emirati Basic Language Survival Kit (2007). Credits and licences