Here are some possible words:
certain, celeron, celadon, celsian, cession
Seven letter words that begin with M and end with Y are:majestymagnifymercurymilitarymonthlymystify
A seven letter word that starts with D and ends with T: decrypt
A seven (7) letter word that starts with M and ends with O: memento
A word that starts with y and ends with y is yay .
Duchess is a seven letter word.