What is the X in X-mas?
"egg-shaped," 1828, from Modern Latin ovoides, a hybrid from Latin ovum (see ovum) + Greek -oeides "like" (see -oid). Related: Ovoidal.
ovoid o·void (ō'void') or o·voi·dal (ō-void'l)n. Something that is shaped like an egg. adj. Shaped like an egg; oviform.