adj. Easily tired or wearied; capable of being fatigued.
the GNU version of the Collaborative International Dictionary of English
adj. Capable of being wearied or tired out.
The Century Dictionary and Cyclopedia
Liable to be wearied.
Word Usage
" A few survivors, precariously perched on sill-less windows, survey their double bind looking for perspective and vanishing points, a place to tip themselves over the edge in hopes defatigable winging."