Interface, Issue, Join, Joining, Joint, Juncture, Kernel, Keystone, Kingpin, Knee, Knuckle, Landmark, Link, Marrow, Meat, Medulla, Middle, Milestone, Mortise, Nave, Navel, Neck, Nucleus, Pin, Pirouette, Pith, Pole, Radiant, Rely, Rest, Revolve, Rotate, Round, Scarf, Screw, Seam, Sheer, Shoulder, Spin, Spindle, Stitch, Substance, Suture, Swing, Swivel, Toggle, Trunnion, Turn, Twirl, Twist, Umbilicus, Union, Veer, Weld, Wheel, Whip, Whirl, Wind, Wrist, Ankle, Arbor, Articulation, Avert, Axis, Axle, Bearing, Boundary, Butt, Centroid, Cervix, Circle, Circulate, Climax, Clinch, Closure, Connection, Core, Cornerstone, Coupling, Crank, Crisis, Crux, Deflect, Depend, Distaff, Divert, Dovetail, Elbow, Embrace, Essence, Essential, Fulcrum, Fundamental, Gist, Gudgeon, Gyrate, Hang, Heart, Heel, Hinge, Hip, Hub