EffectualEffective service; active work.But I will tarry at Ephesus until Pentecost. For a great door and EFFECTUAL is opened unto me, and there are many adversaries. ( 1 Corinthians 1:1 Romans 16:8-9 ) Source: A King James Dictionary. (Used with permission. Copyright © Philip P. Kapusta) Bibliography Information"Entry for 'Effectual'". A King James Dictionary.