Modifiers matching cation:

• soft,
• small,
• undesirable,
• active,
• simple,
• free,
• foreign,
• endogenous,
• charged,
• counter,
• monovalent,
• relevant,
• hydrophilic,
• divalent,
• metal,
• ordinary,
• therapeutic,
• nonvolatile,
• polyvalent,
• mobile,
• complex,
• common,

Simple categories matching monovalent:

• metal,
• cation,
• anion,
• atom,
• group,
• element,
• acid,
• ion,