də̇ˈdendəm, dēˈ- noun
( -s )
Etymology: Latin, neuter of dedendus, gerundive of dedere to give up, deliver, from de from, away + -dere (from dare to give); from the contrast with the addendum of a gear tooth — more at de- , date
: the root of a gear tooth ; also : the distance between the dedendum circle and pitch circle of a gear wheel or rack — compare addendum