Source : Webster's Revised Unabridged Dictionary (1913)

Insinuatingly \In*sin"u*a`ting*ly\, adv.
   By insinuation.

Source : WordNet®

insinuatingly
     adv : in an insinuating manner; "the art book has art to sell,
           insinuatingly, and for a purpose, like the American
           muse, which has in fact a tradition to sell, and one
           which doesn't exist, in painting"