Correct spelling for the English word "ubnt" is [ˈʌbnt], [ˈʌbnt], [ˈʌ_b_n_t] (IPA phonetic alphabet).
The word "ubnt" does not seem to have a widely recognized etymology as it is not a standard or common word in English. It may be a short form or abbreviation of another word or phrase specific to a certain context, industry, or community. Without more information, it is difficult to determine its exact origin or meaning.