Docking is a verb describing the act of stretching one mans foreskin over another mans penis. It can only be practiced between men if one of them is uncircumcised. This "foreplay" is best mixed with a little lube or pre-come prior to the fun begins. Mitch: Hey I been on such a big dry spell with the ladies can I put my cock in your cocks foreskin? Al: Docking's the best, no need to ask!