to fit out (e.g. a ship) with rigging, sails, etc
to prepare (rigging, sails, etc) for use
rig the spinnaker
(usu + out) to clothe or dress (somebody)
(often + out) to supply (somebody or something) with equipment for a particular use
(often + up) to make, assemble, or erect (something), esp for temporary use
[Middle English riggen, prob of Scandinavian origin]