/ Thesaurus / F Synonyms of fine structure Find synonyms for: Noun1. fine structure, spectrum lineusage: the presence of groups of closely spaced spectrum lines observed in the atomic spectrum of certain elements; "the fine structure results from slightly different energy levels"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: grimace Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language