molecular orbital

noun Physics, Chemistry.

See under orbital(def 2a).

Origin of molecular orbital

First recorded in 1930–35

Definition for molecular orbital (2 of 2)

[ awr-bi-tl ]
/ ˈɔr bɪ tl /


of or relating to an orbit.


Physics, Chemistry.
  1. a wave function describing the state of a single electron in an atom (atomic orbital) or in a molecule (molecular orbital).
  2. the electron in that state.

Origin of orbital

1535–45; < New Latin, Medieval Latin orbitālis; see orbit, -al1

OTHER WORDS FROM orbital Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

British Dictionary definitions for molecular orbital

/ (ˈɔːbɪtəl) /


of or denoting an orbit
(of a motorway or major road circuit) circling a large city


a region surrounding an atomic nucleus in which the probability distribution of the electrons is given by a wave function
an orbital road

Derived forms of orbital

orbitally, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for molecular orbital

[ ôrbĭ-tl ]


Relating to an orbit.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for molecular orbital

[ ôrbĭ-tl ]

A partial description of the quantum state of an electron (or other particle) orbiting the nucleus of an atom. Different orbitals have different shapes and orientations, depending on the energy of the electron, its angular momentum, and its magnetic number. Orbitals have no clear boundaries; the shape of an orbital, as depicted graphically, shows only the regions around the nucleus in which an electron has a relatively high probability of being found. No more than two electrons (each with opposite spin) can coexist in a single orbital because of the Pauli exclusion principle. See also probability wave quantum number shell.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.