According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 22 words with the pattern --S-R. That is, five letter words with 3rd letter S and 5th letter R. In alphabetical order, they are:
aesir
baser
doser
easer
hoser
kesar
laser
loser
luser
maser
miser
musar
muser
noser
poser
raser
riser
saser
tasar
taser
visor
wiser
saddler
Here's few more:
sandbar. samovar. sandbur. sampler.
scar, sear, seer, slur, spar, spur, star, stir
Slacker, Silencer, Southerner, Settler, Smarter, etc...
skier
sour soar
starter
soar
A seven letter word that starts with D and ends with T: decrypt
A seven (7) letter word that starts with M and ends with O: memento
Duchess is a seven letter word.
descentdecideddiamonddiscarddiscorddividedelevateerasuregaininggrowingglowinghellishlateralliterallogicalmodicumoreganoreentertangenttrident
cardiac
anxiety
andiron
malaria
stomata
Cabomba
Alveoli.
rotator