-ial

1.
variant of -al1 :
grallatorial.
Origin
extracted from L loanwords in which -ālis -al1 is joined to stems ending in i; cf. filial, imperial
British Dictionary definitions for -ial

-ial

suffix
1.
of; relating to; connected with: managerial
Word Origin
from Latin -iālis, adj suffix; compare -al1
Word Origin and History for -ial

variant of -al (1).