There are no American English words that meet those rules, but here are some nine-letter words starting with N and ending with A:
nanotesla, natatoria, naumachia, nemophila, neophilia, neoplasia, nephridia, neuralgia, neuroglia, neuromata, nicotiana, nostalgia
"BIOTRON"
no. no.
letters
tempura
lime !
whiff, wahoo, whirr
Overnight sojourn
Those are consecutive letters in the English alphabet, starting with the letter 'k' and ending with the letter 'n'.
teddy
Feminist and finalist are 8 letter words. They end with the letters IST.
The letters spell the 7 letter word askance. They do not spell a 7 letter word starting with s and ending with e.
There are no 6 letter words that contain the 7 letters igwnaeb. The letters can be used to spell words such as began, begin and binge.