/ Dictionary / Index L L-line: Meaning and Definition of Find definitions for: L-line Pronunciation: (el'līn"), [key] — n. Physics. one of a series of linesin the x-ray spectrum of an atom corresponding to radiationcaused by the transition of an electron to the L-shell. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Llewellyn LL.M. Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language