barrier - problem, restriction, obstacle⏎
cap - limit, surpass⏎
curtail - limit, reduce, shorten, cut⏎
array - collection, group, number (of)⏎
ability - skill, intelligence, competence, experience, expertise, capability⏎
downgrade - reduce status, reduce value, make less important⏎
dimension - size, aspect⏎
clearance - permission, sanction, leave⏎
compulsory - obligatory, binding, incumbent, mandatory⏎
defective - faulty, imperfect, incomplete⏎