1.  whole: having every necessary part or everything that is wanted
2.  finished: having reached the normal or expected end 
3.  absolute: being the greatest degree of something 

  As we begin chapter 15, verse one we must be prayerful and ask God for wisdom and discernment and knowledge >

It reads that John saw another sign in heaven , great and marvelous , seven angels having the seven last plagues , for in them the wrath of God is complete >

 I like all three meanings of the word complete as shown here, whole , finished , complete. Read these meanings carefully , you know when you have read them and referred back to this verse that the end is near . The last 7 judgements are about to descend on mankind >