Modifiers matching association:

• voluntary,
• civic,
• informal,
• contractual,
• global,
• positive,
• formal,
• collaborative,
• visual,
• affiliated,
• cooperative,
• political,
• private,
• ordinary,
• autonomous,
• intimate,
• scientific,
• sporting,
• crucial,
• expressive,
• larger,
• secondary,
• cultural,
• occupational,
• meaningful,
• national,
• criminal,
• mathematical,
• specialized,
• scholarly,
• involuntary,
• large,
• medical,
• ecological,
• social,
• societal,
• violent,
• sexual,
• important,
• athletic,
• strong,
• industrial,
• semantic,
• exclusive,
• intermediate,
• civilian,
• outside,
• observed,
• benevolent,
• primary,
• independent,
• urban,
• modern,
• bureaucratic,
• free,
• entrepreneurial,
• international,
• communal,
• secular,
• hierarchical,
• foreign,
• economic,
• nonprofit,
• functional,
• legal,
• corporate,
• external,
• civil,
• dangerous,
• relevant,
• stable,
• musical,
• spatial,
• local,
• traditional,
• organized,
• concrete,
• close,
• religious,
• influential,
• permanent,
• indian,
• new,

Simple categories matching voluntary:

• system,
• association,
• organization,
• behaviour,
• helper,
• option,
• society,
• committee,
• group,
• organisation,
• work,
• behavior,
• activity,
• alternative,
• contribution,
• club,
• institution,
• deposit,
• body,
• choice,
• sector,
• service,
• endeavor,
• transport,
• donation,
• migrant,
• participation,
• action,
• measure,
• market,
• unit,
• movement,
• information,
• abstinence,
• item,
• vessel,
• task,
• agency,
• effort,
• assistance,
• grouping,
• project,
• control,
• agreement,
• force,
• school,
• arrangement,
• easement,
• motion,