assailable

/əˈseɪləbəl/

Anything vulnerable to attack is assailable. If your castle is assailable to attack by enemy marauders, you may need to dig a deeper moat!

This adjective's antonym, unassailable, which means both "well-defended" and "without flaws or loopholes," is much more common. Still, you should feel free to use assailable for things that can either be hurt or easily disproven, like your sister's assailable claim that she couldn't have eaten the last cookie because she doesn't even like chocolate. Assailable comes from assail, "attack violently," and its Latin root meaning "to leap toward."

Definitions of assailable

1. adjective

   not defended or capable of being defended
   synonyms: open, undefendable, undefended

   vulnerable

   susceptible to attack