unseizable

un- +‎ seizable

unseizable (comparative more unseizable, superlative most unseizable)

1. That cannot be seized or grasped.
   • 1885, Annie Besant, Autobiographical Sketches‎:

     A large packet of 'Text Books'--left for that purpose by Norrish, if the truth were known-- whose covers were the same color as those of the 'Fruits', attracted Mr. Outram's attention, and he took off some of the brown paper wrapper, but found the goods unseizable.

   • 1897, Mrs. Cashel Hoey.], Facing the Flag‎:

     He eluded all pursuit, and his name--or at least the name he gave himself--was known all over the world, and inspired horror and terror everywhere, as being that of a legendary personage, a bogey, invisible and unseizable.

   • 1913, Edith Wharton, The Custom of the Country‎:

     For a moment she was lost in the pursuit of an unseizable clue--the explanation of this monstrous last perversity of fate.

• unsizeable