The story
From the drosophila gene Brahma or brm, where it occurs as a structural motif, and domain. Not related to bromo- (“bromine”).
Etymology from Wiktionary, CC BY-SA 4.0.
bromodomain
Today it means: A protein domain that recognises acetylated lysine residues such as those on the N-terminal tails of histones, often a prerequisite for protein-histone association and chromatin remodeling. Full definition →