Correct spelling for the English word "bruning" is [bɹˈuːnɪŋ], [bɹˈuːnɪŋ], [b_ɹ_ˈuː_n_ɪ_ŋ] (IPA phonetic alphabet).
The word "bruning" does not seem to have a widely recognized etymology. It is possible that it could be a variant or misspelling of "burning". However, without any additional context or information, it is challenging to determine a precise origin or linguistic history for the term.