-ium /-i-əm/

1. Forming nouns denoting: a metallic element, as in plutonium
2. A group forming a positive ion, as in ammonium
3. A biological structure, as in conidium

• period piece
• period pieces
• periods
• periods of grace
• perionychia
• perionychium
• Periophthalmus
• periost
• periostea
• periosteal
• periosteum
• periostites
• periostitic
• periostitis
• periostraca
• periostracum
• periostracums
• periotic
• periotics
• peripatetic
• peripatetical
• peripateticism
• peripateticisms
• peripatetics
• Peripatus