In a crafty or surreptitious manner (5)
I believe the answer is:
slyly
(Other definitions for slyly that I've seen before include "In a cunning manner" , "Craftily, cunningly" , "in underhand way" , "In a stealthy and secret way" .)
I believe the answer is:
slyly
(Other definitions for slyly that I've seen before include "In a cunning manner" , "Craftily, cunningly" , "in underhand way" , "In a stealthy and secret way" .)