cupule
Noun
Meaning
A cuplet or little cup, as of the acorn; the husk or bur of the filbert, chestnut, etc.
A sucker or acetabulum.
Source: Webster's dictionarySynonyms
acorn cup
bowl
well
socket
domed
cupola
acetabular
Thunderdome
calyculus
caliculus
acetabulum
dome-shaped