1) Apposable 2) Can be battled against 3) Like our thumbs 4) Open to contravention 5) Subject to being challenged 1) Apposable 
• (a.) Capable of being opposed or resisted. • (a.) Capable of being placed opposite something else; as, the thumb is opposable to the forefinger.
Op·pos'a·ble adjective 1. Capable of being opposed or resisted. 2. Capable of being placed opposite something else; as, the thumb is opposable to the forefinger. 
[adj] - capable of being placed opposite to something
apposable adjective capable of being placed opposite to something; `the thumb is opposable to the forefinger`
The capability of being placed against the remaining digits of a hand or foot; e.g., the ability of the thumb to touch the tips of the fingers on that hand.
capable of being placed opposite to something else: the opposable thumb of primates. · capable of being resisted, fought, or opposed.
Capable of being placed opposite something else; said of the first toe of an opossum in the sense that it can be placed opposite each of the other toes on that same foot.