1. Spinous.

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

• zcanthous,
• scanthous,
• wcanthous,
• qcanthous,
• axanthous,
• avanthous,
• afanthous,
• adanthous,
• acznthous,
• acsnthous,
• acwnthous,
• acantous,
• acanthus,
• acanthos,
• accanthous,
• akanthous,
• acanthuse,
• acanthuss,
• accanthos,
• akanthos

• acanthocyte,
• acanthoid,
• accentor,
• acanthotic,
• acanthoma,
• acanthaceae,
• accent,
• acanthophis,
• acantholysis,
• acanthisitta,
• aconite,
• acanthion,
• acanthurus,
• acanthosis,
• acanthus.

The adjective form of the word "acanthous" is "acanthoid".

The plural form of the word "acanthous" is "acanthi".

The singular form of the word "acanthous" is "acanthus"