Skinny-dipping is a recreational activity in which a person swims nude, without any clothing. It is also known as night swimming or midnight swimming. The term 'skinny-dipped' is derived from the act of swimming in the nude. The crossword solution for this term is 'swam', which is a verb meaning to move through water by using one's limbs, especially the legs. Skinny-dipping is often done in private, secluded areas such as lakes, rivers, and oceans.