I. ˈpivəd. ə l, -ət ə l adjective
Etymology: International Scientific Vocabulary pivot (I) + -al
1.
a. : of or relating to a pivot
correct pivotal dimensions
b. : constituting or functioning as a pivot
a pivotal shaft
2. : that vitally affects the activity or development or course of something : central in importance, function, influence, or effect
holds a pivotal position
one of the great pivotal points of the war — S.L.A.Marshall
II. noun
( -s )
: something that is pivotal