18-letter words containing a, c, u, m
- unit magnetic pole — the unit of magnetic pole strength equal to the strength of a magnetic pole that repels a similar pole with a force of one dyne, the two poles being placed in a vacuum and separated by a distance of one centimeter.
- upper middle class — wealthy, highly-educated people
- urban contemporary — popular dance music incorporating elements of rap, rhythm-and-blues, funk, and soul.
- victor emmanuel ii — 1820–78, king of Sardinia 1849–78; first king of Italy 1861–78.
- widemouth blindcat — any of several catfishes, as Satan eurystomus (widemouth blindcat) of Texas, that inhabit underground streams and have undeveloped eyes and unpigmented skin.