As adjectives the difference between naggiest and saggiest
is that naggiest is superlative of naggy while saggiest is superlative of saggy.
naggiest
English
Adjective
(head)
(naggy)
naggy
English
Adjective
(er)
Prone to nag, irritable
saggiest
English
Adjective
(head)
(saggy)
saggy
English
Adjective
(er)
Baggy or loose-fitting.
That sinks or droops from wear or its own weight.