ECLAIR
ECLAIRCISSEMENT
ECLAIRS
ECLAMPSIA
ECLAMPSIAS
ECLAMPSIES
ECLAMPSY
ECLAMPTIC
ECLAT
ECLATS
ECLECTIC
ECLECTICALLY
ECLECTICISM
ECLECTICISMS
ECLECTICS
ECLIPSE
ECLIPSED
ECLIPSER
ECLIPSERS
ECLIPSES
ECLIPSING
ECLIPSIS
ECLIPSISES
ECLIPTIC
ECLIPTICALLY
ECLIPTICS
ECLOGITE
ECLOGITES
ECLOGUE
ECLOGUES
ECLOSE
ECLOSED
ECLOSES
ECLOSING
ECLOSION
ECLOSIONS

36 words start with ECL.