burn (v.) 12c., combination of O.N.
brenna "to burn, light," and two originally distinct O.E. verbs: bærnan "to kindle" (trans.) and beornan "to be on fire" (intrans.), both from P.Gmc. *
brennan, *branajan (cf. M.Du. bernen, Du. branden, O.H.G. brinnan, Ger. brennen, Goth. brannjan), perhaps from PIE *gwher- "to heat, warm" (see
warm), or from
PIE *bhre-n-u, from root
*bhreue- "to boil forth, well up" (see
brew). Related: Burned; burning.
PIE Proto-Indo-European, the hypothetical reconstructed ancestral language of the Indo-European family. The time scale is much debated, but the most recent date proposed for it is about 5,500 years ago.