Here are some possible words:
cabochon
calderon
calfskin
Cambrian
campaign
Canadian
cannabin
cannelon
capeskin
capetown
capuchin
carageen
cardamon
cardigan
careworn
carillon
cauldron
cerulean
cesarean
cesarian
cetacean
chainman
chainmen
chairman
chairmen
chaldron
champion
chaperon
chaplain
chessman
chessmen
children
choreman
choremen
christen
cinnamon
cinquain
citation
civilian
clansman
clansmen
coachman
coachmen
coaction
coercion
cognomen
cohesion
collagen
colophon
comedian
comedown
complain
conation
conquian
coonskin
cooption
cordovan
corpsman
corpsmen
cotillon
countian
coxswain
cragsman
cragsmen
crankpin
creation
cryotron
cultigen
cyanogen
cyclamen
Some very C words are:
The longest word (found in Webster's) beginning with C and ending in N is twenty-two letters long:
counterexcommunication
Strange as it may seem, all 33 sixteen-letter words beginning with C and ending in N are the same length:
canaliculization
cephalorachidian
cerebrorachidian
characterization
chondropterygian
chymotrypsinogen
circumambulation
circumdenudation
circumnavigation
circumundulation
coadministration
collectivization
collodionization
complexification
congeliturbation
consignification
contraindication
copolymerization
corporealization
counteragitation
counterassertion
counterextension
counterimitation
counterlatration
countermigration
counterobjection
counterradiation
counterselection
countervallation
countervibration
criminalistician
cuticularization
cycadofilicinean
The longest word I could locate is nondiscrimination. The word contains 17 letters.
abrogate
incubateimmolateirritateinsulateintimateinscribe
Scissors is an 8 letter word. It begins and ends with S.
rutabaga
The word sabotage is a eight letter word.
fernando?
Trusting
NegativE
tortoise
biblican
Numbered
Wingitts