ER
ERA
ERADIATE
ERADIATED
ERADIATES
ERADIATING
ERADIATION
ERADIATIONS
ERADICABLE
ERADICABLY
ERADICANT
ERADICANTS
ERADICATE
ERADICATED
ERADICATES
ERADICATING
ERADICATION
ERADICATIONS
ERADICATIVE
ERADICATOR
ERADICATORS
ERAS
ERASABILITIES
ERASABILITY
ERASABLE
ERASE
ERASED
ERASEMENT
ERASEMENTS
ERASER
ERASERS
ERASES
ERASING
ERASION
ERASIONS
ERASURE
ERASURES
ERATHEM
ERATHEMS

39 words start with ERA.