vac·uum (văkym, -yəm, -y-əm)
n. pl. vac·uums or vac·u·a (-y-ə)
a. Absence of matter.
b. A space empty of matter.
c. A space relatively empty of matter.
d. A space in which the pressure is significantly lower than atmospheric pressure.
2. A state of emptiness; a void.
3. A state of being sealed off from external or environmental influences; isolation.
4. pl. vac·uums A vacuum cleaner.
1. Of, relating to, or used to create a vacuum.
2. Containing air or other gas at a reduced pressure.
3. Operating by means of suction or by maintaining a partial vacuum.
tr. & intr.v. vac·uumed, vac·uum·ing, vac·uums
To clean with or use a vacuum cleaner.
[Latin, empty space, from neuter of vacuus, empty, from vacāre, to be empty; see euə- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 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.