WU: Wuss
Also, just about any word could have been used twice. Aardvark for AR, DV, VA…
WU - blowup
WV = dewvaporation
But I don’t thknk any has yet, and would be extremely improbable except for a word that has two very uncommon pairs, as awkward does.
WX = Viewx software.
WY = Wyoming
WZ: Frowzy
Missed one.
WW = yellowwood
(Which is fun to spell out loud: y-e-double l-o-double double u-double o-d.)
XB = oxbow
XA = exam
XC = excellent
XD = sexdecillion
10 to the 51st power.
XE: Xenon
XF = exfoliant or Oxford
XG - foxglove
XH = foxhound
(OK, what the hell . . . )
XI = foxier
XJ = Loxjet
Liquid Oxygen Torch System
XK: exkaiser
XL = axle
XK = boxkeeper
XM: taxman
XN: Laxness
XO: axolotl (or saxophone)