bulimic
One such word is format.
thorntail
form
The letter f can be changed to g to form the word ginger.
Cordial.
The word "letter" contains two morphemes: "letter" itself, which is a free morpheme that can stand alone as a word, and the plural suffix "-s" if considering the plural form "letters." However, in its singular form, "letter" is just one free morpheme. Thus, in its singular form, "letter" has one morpheme.
noodle
Define
Write
Giant
ode
Closure