1) Absurdly 2) Blankly 3) Doltishly 4) Foolishly 5) Insensitively 6) Uselessly 1) Doltishly 2) Foolishly 3) Imprudently 4) In a dumb manner 5) In a silly way 6) In a stupid manner 7) In a thickheaded way 8) In an inane manner 9) Irrationally 10) Like a ninny 11) Thoughtlessly 12) Unwisely 13) Without thinking 14) Witlessly 
[adv] - in a stupid manner
stupidly 1. In a stupid manner. 2. A moment or act of stupidity.
doltishly adverb in a stupid manner; `he had stupidly bought a one way ticket`