cymatium

[si-mey-shee-uh m, sahy-] /sɪˈmeɪ ʃi əm, saɪ-/
noun, plural cymatia
[si-mey-shee-uh, sahy-] /sɪˈmeɪ ʃi ə, saɪ-/ (Show IPA).
Architecture
1.
the uppermost member of a classical cornice or of a cornice of similar form: usually a cyma recta in classical examples.
Compare sima2 .
2.
echinus (def 2c).
Origin
1555-65; < Latin < Greek kȳmátion, equivalent to kȳmat- (stem of kŷma wave; see cyma) + -ion diminutive suffix
British Dictionary definitions for cymatium

cymatium

/sɪˈmeɪtɪəm; -ʃɪəm/
noun (pl) -tia (-tɪə; -ʃɪə)
1.
(architect) the top moulding of a classical cornice or entablature
Word Origin
C16: see cyma