There are numerous words ending in eny, for eg. Cryogeny, orogeny, progeny, larceny, sheeny, greeny, teeny, weeny. there is only one four letter word though and that is deny.
The word is dreamt.
roweny
tranq
spent
sent
Underground
Dreamt - the past tense of dream
No, there is no word in the English language that starts and ends with the letter "x."
No word in the English language begins with U and ends with J.
No word in the English language begins with sh and ends with cy.
The happiest word in the English language that starts and ends with "S"= "smiles". For Spanish, it's "sonrisas", which means the same thing.
There is one Old English word it is "Slowh"