• penniness,
• penines,
• oennines,
• lennines,
• -ennines,
• 0ennines,
• pwnnines,
• psnnines,
• pdnnines,
• prnnines,
• p4nnines,
• p3nnines,
• pebnines,
• pemnines,
• penninses,
• pennins,
• peninnes,
• tennines,
• Pennenees,
• Pennens

• peninsular,
• pennington,
• penoncel,
• pennoncel,
• pennoncelle,
• penning,
• penance,
• peninsula.

The adjective form of the word "Pennines" is "Pennine".

The plural form of the word "Pennines" remains as "Pennines".

The singular form of the word "Pennines" is "Pennine"