XP = expertise
XQ - exquisite
XR: ExRx
XS = Xs
More than one X, used by those who think it is faux pas to use an apostrophe in a plural.
Classic Fauxs & Finishes sells home decor items.
XT = foxtrot
XU: Exurban
XV = XVoice
a voice-over company providing telephone service over broadband
XW: boxwood.
XX: Xx (band)
XY: xylophone
XX = Wikipedia has bio articles on 14 different people with the surname Foxx. A google search for ‘maxxed’ gets 360,000 hits. Mexico’s XX Beer is pronounced Dos Equis.
XZ - Cytauxzoonosis
YA - papaya
YB - ladybug
YC = babycakes
I’ll refrain from linking to the Neil Gaiman story of the same name because, well, ew.
YD - payday
YE - layer
YF - kayfabe
YG: polygon
YH: Anyhow
YI: flying.
YJ: Pyjamas