Native speaker
In Emirati Arabic, “Thick” is سمين (smeen).
سمين
Thick
It's in the phrasebook under Yes, no & everyday basics, with 90 more like it.
sagheer
dha'eef
gaseer
'areedh
dhayeeg
imdawwar
Source: DLIFLC Emirati Basic Language Survival Kit (2007). Credits and licences