Definition of ovalling in English:
ovalling
(also ovaling)
noun ˈəʊv(ə)lɪŋˈəʊv(ə)lɪŋ
Mechanics Becoming oval; adopting an oval form or (especially) cross-section.
Origin
Late 16th century; earliest use found in Robert Dallington (b. 1561), author and courtier. From oval + -ing.