/ Dictionary / Index G Geiger-Müller threshold: Meaning and Definition of Find definitions for: Gei'ger-Mül'ler thresh"old Pronunciation: (gī'gur mul'ur, -my'lur), [key] — Physics. Physics. the minimum voltage applied to an ionization chamber, as in a Geiger counter, at which the charge collected per count is independent of the nature of the ionizing event producing the count. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Geiger counter Geiger-Müller tube Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language