| Word | Definitions | Synonyms |
|---|---|---|
| theca | (noun) outer sheath of the pupa of certain insects | - |
| (noun) a case or sheath especially a pollen sac or moss capsule | Synonyms: sac | |
| thecodont | (noun) presumably in the common ancestral line to dinosaurs and crocodiles and birds | Synonyms: thecodont reptile |