Short Words:
* ant
* ate
* ear
* eat
* era
* rat
* sea
* tan
* tea
* ten
* art
* ran
* sat
* set
* air
* aisle
* lane
* near
* rent
* stain
* steer
* tern
* tears
* tales
Longer Words:
* antern
* least
* least
* rental
* stainer
* stern
* stainer
* strain
* slattern
* strenuous
* teas
* tanner
Bonus:
* serene (if we allow rearranging letters)
This is not an exhaustive list, but it gives you a good starting point. Let me know if you want to try to find more!