There are 26 words that would match that criteria:
Sachem
Sacrum
Sadism
Salaam
Schism
Scream
Scutum
Seldom
Sensum
Septum
Sexism
Shalom
Shazam
Sholom
Siglum
Simoom
Sitcom
Slalom
Sodium
Spirem
Sputum
Squirm
Stream
Subgum
Syncom
System
Alkali.
racecar
squawkstreak
Quaint is a 6 letter word that begins with the letter q and ends with t.
zealot
talenttyrantteapottickettrivettenant
baobab.
forsho
bamboo
Raiden
embalmemblemesteem
Six letter words that start and end with R:rafterraiderrancorrangerrapierraptorrasherratherreaderreaperrectorreeferrenderrenterrepairricherrigourringerripperrobberrockerrollerromperrooferrosterrubberrudderrunner