Cannon pinion, is the clutch pinion that drives the motion-work which in turn drives the hands. The minute hand is usually pushed onto the cannon pinion.
Addendum in a pinion or wheel is that part of each tooth between its tip and the pitch-circle.
Epicycloidal the form of an epicycloid: epicycloidal gear, epicycloidal profile teeth.
Hobbing, "Cutting by means of a worm-hob. In hobbing, the worm-hob has two different motions: a rotary motion in connection with that of the wheel that is being cut, and a longitudinal shift (along the axle of the wheel)." (Berner)
Hour-wheel, the wheel upon which the hour hand sits turning twice every 24 hours.
Intermediate wheel/pinion, a piece connecting two principle components.
Minute wheel, driven by the cannon pinion, in turn driving the hour wheel.
Pinion, "A watch part, generally with 6 to 14 leaves (teeth). The different parts of the pinion are the leaves, the seat to which the wheel is riveted, the shank and the pivots." (FHH)
Pitch, "In a gear, the circular pitch p is the distance between two consecutive teeth, measured on the pitch-circle a. If r is the radius of the pitch-circle, d the pitch-diameter and z the number of teeth. " (Berner)
Pivot, a part of an axle that turns in a bearing. Cylindrical pivots are usually rounded off at the end. This type of pivot turns on the walls of the jewel-hole or bushing.
Train, a series of wheels in a movement, a 'going-train' traditionally leads to the escapement.