Examples from the Web for indefinable
He had that indefinable sixth sense that distinguishes gifted warriors from good ones.Mike Leach Tackles Geronimo the Motivational Murderer|James A. Warren|August 17, 2014|DAILY BEAST
He knew what was going on and he never, in my experience, took risk that was indefinable.
There had suddenly sprung up that indefinable atmosphere of the sick-room—a sick-room in which a fight is being waged.Fanny Herself|Edna Ferber
It possessed a beauty that left me helpless—yet there was an indefinable sadness in it that might have suggested a haunting fear.Wings of the Wind|Credo Harris