Hundreds of eight letter words begin and end with the letter S. Some of those words include Sabbaths, saltines, sandlots, saplings, sardines, sausages, scallops, scalpers, scholars, scooters, seagulls, seamless, seizures, settings, shampoos, shotguns, sideways, skyboxes, slippers, smarties, snowcaps, softness, sponsors, stations, subtexts and suffixes.
Diabetic and dogmatic are 8 letter words. They begin with D and end with C.
chic, bric-a-brac, torc, epic, ...
Sardonic
Silicic
Narc
Sandman (starts with S ends with N - 7 letter word)
Ability is a 7 letter word.
falloff
chaotic
A seven (7) letter word that starts with M and ends with O: memento
Santana
undoing
rotunda
yeshiva.
Hosanna
essence
Strains