turquiose
Some five letter words with second letter U and fifth letter T are:auditbuiltburntburstcubitduvetguestguiltoughtquartquestquiltquintwurst
trillionth
court
Meant or beret.
aaologist
geneticsenatorlengthsjanitormonitormonster
Boastful
That wants to be "vacationer."
No, it isn't a "U" as the letter U is a vowel (along with A, E, I and O). The fifth consonant in the sentence is the letter "T" in the word Fifth.
Whistle
eighths, quarter, treated, treater, breathe, wreaths,