1. For a moment or an instant.
2. In a moment; very soon.
3. Usage Problem At the moment; for the time being.
Usage Note: Momentarily is widely used in speech to mean "in a moment, shortly," as in The manager is on another line, but she'll be with you momentarily. Many critics dislike this use, insisting that the adverb should only be used to mean "for a moment," as in He hesitated momentarily before entering the room. But the Usage Panel's resistance to the nontraditional use has waned over time. For the first example above, the Usage Panel acceptance rate was 59 percent in 1988, 68 percent in 1999, and 83 percent in 2013. Also in 2013, 63 percent of the Panel approved of the vaguer use of momentarily in the sense of "at the moment" where the length of time is open-ended, as in The file server is momentarily out of order. This figure is up slightly from the 58 percent acceptance rate for the same sentence in 1999.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.