1. Full of mountains; large as a mountain; huge; inhabiting mountains.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• mountaines,
• mountainds,
• mountaintour,
• mountanous,
• countinous,
• mountainouse,
• mountainss,
• moutainus,
• mountaints,
• mountaionous,
• mountainess,
• mountianous,
• mountainus,
• moutainous,
• mountanious,
• mountaious,
• mountenous,
• mountaneous,
• montainous,
• moutinous

• mountain mint,
• mountain man,
• monotonous,
• mountain grape,
• montanaro,
• mountain bike,
• mountain rice,
• montanan,
• mountain pass,
• mounting,
• mountain range,
• mountain goat,
• Mountain Nyala,
• mountainside,
• mountain trail,
• mountain chain,
• mountain sumac,
• mountain heath,
• monition,
• mountain pride,
• mountain fern,
• mountain lion,
• mountain,
• mountain sheep,
• Mountain Avens,
• Montanye,
• mountain rose,
• mountain state,
• mountain daisy,
• mountain pine,
• mountain zebra,
• mountain birch,
• mountain devil,
• mountain lily,
• mountain skink,
• mountain phlox,
• mountain alder,
• Mountain Paca,
• mountaineering,
• Mountain Rimu,
• montanez,
• mountain time,
• mountain tea,
• mountain maple,
• mountain peak,
• montandon,
• mountain quail,
• mountain ebony,
• mountain oak,
• monotonously,
• mountain box,
• mountaineer,
• mountain fever,
• mountain ash,
• mountain tent.

The adjective form of the word "mountainous" is "mountaintop" or "mountainlike".

The plural form of the word "mountainous" is "mountainous".

The singular form of the word "mountainous" is "mountain"