ad lib, assailability, breakability, breakableness, brittleness, chink, crackability, crackableness, crispness, crumbliness, crushability, crushableness, delicacy, disqualification, exposure, extemporaneousness, fissility, flimsiness, fracturableness, fragility, frailty, frangibility, friability, heel of Achilles, improvisation, incapability, incompetence, lacerability, lack of preparation, liability, nonpreparation, nonpreparedness, openness, penetrability, planlessness, pregnability, soft spot, susceptibility, susceptivity, unfitness, unfittedness, unpreparedness, unqualification, unqualifiedness, unreadiness, unsuitability, unsuitableness, unsuitedness, vincibility, vulnerable point, weak link, weak point, weakness