ostensibly

adverb1

1. •
   Seemingly, apparently, on the surface; supposedly, according to representations or implications made by someone (especially when their motives are suspected by others).

   • His interest in the railway was ostensibly a hobby, but people began wondering why he was taking photos of specific trains and specific equipment.
   • Her interest in his welfare was ostensibly charitable and magnanimous, but people began wondering who was going to inherit his assets when he died.