< /əˈdɛn də/ for 1, 2; ad·den·dums for 3.
- a thing to be added; an addition.
- an appendix to a book.
- the radial distance between the tip of a gear tooth and the pitch circle of a gear or the pitch line of a rack.Compare dedendum.
- Also called addendum circle.an imaginary circle touching the tips of the teeth on a gear.
noun plural -da (-də)
- something added; an addition
- a supplement or appendix to a book, magazine, etc
- the radial distance between the major and pitch cylinders of an external screw thread
- the radial distance between the pitch circle and tip of a gear tooth
1794, literally “something added,” from Latin addendum, neuter of addendus “that which is to be added,” gerundive of addere (see add (v.)). Classical plural form is addenda.