Early 18th century; earliest use found in Nathan Bailey (d. 1742), lexicographer and schoolmaster. From classical Latin modificāre + -able. Compare post-classical Latin modificabilis.
Definition of modificable in US English:
modificable
adjectiveˈmɒdɪfɪkəbl
rare
Modifiable.
Origin
Early 18th century; earliest use found in Nathan Bailey (d. 1742), lexicographer and schoolmaster. From classical Latin modificāre + -able. Compare post-classical Latin modificabilis.