Emailed.

[Ancientreg]

Large semi circular mouldings in architecture. 4 letters

[JJ109]

Cyma
https://www.collinsdictionary.com/dictionary/english/cyma

[dannyk13]

Tori

[Mamyalynne]

Tori

[andres]

arch

[Mamyalynne]

Torus

plural Tori


ARCHITECTURE
a large convex moulding, typically semicircular in cross section, especially as the lowest part of the base of a column.

[JJ109]

also Bead
http://doric-column.com/glossary_classical_architecture.html

[dannyk13]

Plural of Torus
https://www.wrp-timber-mouldings.co.uk/moulding-profiles/profiles/torus

[Mamyalynne]

I agree there are alternatives in the singular, the clue asks for a plural.