1. A sheath or case; the seed-case of a fern.

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

• thaca,
• rheca,
• fheca,
• gheca,
• yheca,
• 6heca,
• t6heca,
• thneca,
• tjheca,
• thesca,
• thecza,
• teca,
• tehca,
• theac,
• thecca,
• thmca,
• thega,
• Thecah,
• thica,
• tcheca

• thwack,
• thick,
• thuja,
• These,
• Those,
• thc,
• THz,
• thies,
• thach.

The adjective form of the word "theca" is "thecal".

The plural of the "theca" can be the "thecae".

The singular of the "theca" can be the "theca".