neudobno

1. (physically) uncomfortably
   Ceo let sam sedeo neudobno i nisam spavao. — I sat uncomfortably the whole flight and didn't sleep.
   Neudobno mi je u ovim novim cipelama. — I'm uncomfortable in these new shoes.

Neudobno usually refers to physical discomfort only. For 'awkward, ill at ease' say nelagodno or neprijatno: Osećao sam se nelagodno među nepoznatim ljudima; osećam se neudobno in that sense is a calque from Russian or English.