Adding a single vowel (a, e, i, o, u, y) does not make any common English words using those letters.
You can add an A to spell m-dash (em dash).
You can add an E to spell M Shed (a museum in Bristol).
But you would need to add two vowels (A and E) to spell a common word, shamed or mashed.
mashies, messiah
The letters 'xnlni' cannot unscramble to spell one word. The longest possible word is linn.
The letters 'rneeetpta' unscramble to spell the word penetrate.The next longest possible word is patentee.
The letters 'iralreug' cannot unscramble to spell a single word. The longest possible word is regular.
The letters 'anlcopmi' unscramble to spell the word complain.The next possible longest word is campion.
reezcva == ==
Sleigh.
Autographs.
Crooked.
Termination.
Dandelion.
understand
symbol.