Note: these 'words' (valid or invalid) are all the permutations of the word duet. These words are obtained by scrambling the letters in duet.
Definitions and meaning of duet
From Italianduetto(“short musical composition for two voices”), diminutive of duo(“two”).
IPA(key): /djuˈɛt/, /duˈɛt/
(music) A musical composition in two parts, each performed by a single voice (singer, instrument or univoce ensemble).
(music) A song composed for and/or performed by a duo.
A pair or couple, especially one that is harmonious or elegant.
(musical composition in two parts):duo
(pair or couple):couple, pair, twosome; see also Thesaurus:duo
duet (third-person singular simple presentduets, present participleduettingordueting, simple past and past participleduettedordueted)
(intransitive) To perform a duet.
1822, Lord Byron, Letter to Mr. Moore, Pisa, July 12, 1822, in The Letters of George Gordon Byron, edited by Mathilde Blind, London: Walter Scott, 1887, p. 277, 
When you can spare time from duetting, coquetting, and claretting with your Hibernians of both sexes, let me have a line from you.
1879, George Meredith, The Egoist, Chapter 20, 
He was about as accordantly coupled with Dr. Middleton in discourse as a drum duetting with a bass-viol […]
2011, Julian Barnes, The Sense of an Ending, Random House Canada, p. 45, 
‘Ti-yi-yi-yime is on my side, yes it is,’ I used to yodel, duetting with Mick Jagger as I gyrated alone in my student room.
(intransitive, zoology, of pairs of animals) To communicate (warnings, mating calls, etc.) through song.
1975, Edward O. Wilson, Sociobiology: The New Synthesis, Belknap Press, p. 223,
Duetting species are typically monogamous.
1986, Thomas A. Sebeok, I Think I Am a Verb: More Contributions to the Doctrine of Signs, New York: Springer Science+Business, 2013, Chapter 7, p. 87, 
In several dozen species of birds there has been found a phenomenon known as duetting, or antiphonal singing: the first part of a song is executed by one partner of a pair, then the other partner very promptly chimes in to sing the second part.
(transitive) To perform (sing, play, etc.) as a duet.
1939, James Joyce, Finnegans Wake, Oxford University Press, 2012, p. 377,
Peena and Queena are duetting a giggle-for-giggle […]
1941, Emily Carr, Klee Wyck, Chapter 1, 
After the Lord's Prayer the Missionaries duetted a hymn while the children stared at me.
(transitive) (of two people) To say at the same time, to chorus.
1864, Charles Whitehead, “The Stock-Broker” in Heads of the People: or, Portraits of the English, Volume I, London: Henry G. Bohn, p. 23, 
“My dear papa!” duetted the girls; but there was something in the husband and father's face, that told the three ladies it would be worse than useless to raise that question at present.
1884, Anonymous, A Speculation, Denver: D. M. Richards, Chapter 12, p. 50, 
“A bear!” exclaimed the Major, jumping up and coming forward.
“A bear!” dueted the Doctor and Right Rev., pressing hastily to the front.
In the UK and other Commonwealth countries, the present and past participles of this verb are often spelled with a double T: duetted and duetting
'tude, -tude, Deut., tude
Borrowed from Italianduetto or GermanDuett (itself borrowed from Italian).
duetn (pluralduetten, diminutiveduetjen)
A duet (musical piece performed by two players or two singers).
A ballet routine performed by two dancers.
→ Indonesian: duet
→ West Frisian: duët
From Dutchduet, from Italianduetto or GermanDuett (itself borrowed from Italian).