Answer: busiest

AnswerCrossword Clue
BUSIESTLike the most active bee?
BUSIESTLeast likely to be free
BUSIESTMost industrious.
BUSIESTMost hectic
BUSIESTAdjective for Atlanta's Hartsfield airport
BUSIESTSuperlative for Atlanta International Airport
busiestfull of activity
busiestactively employed
busiestto make or keep busy
busiestBUSY, occupied