1. Capable of being added or added to
   - addable

See also: add, additive

• efficient
• efficiently
• effigy
• effing
• effleurage
• effloresce
• efflorescence
• efflorescent
• effluence
• effluent
• effluvial
• effluvium
• efflux
• effluxion
• effort
• effortful
• effortfulness
• effortless
• effortlessly
• effortlessness
• effrontery
• effulgence
• effulgent
• effuse
• effusion