SASSY or SORRY
Some examples of five-letter words that begin and end with the same letter are: radar, level, civic, minim, and kayak.
ponys
Blunt
array
American 'meter' = British 'metre'
queue
One word is Madam.
The word is "queue."
empty
Here's an example of a five letter word which reads the same when the first and last letters are dropped: gnome and nom (as in 'nom de plume')
snail
SWIMS