gymno-, gymn-

(Greek: unclothed, bare, unclad, disrobed, undressed; naked, nude)

gymnospore (s) (noun), gymnospores (pl)
Usually uncovered single-celled reproductive bodies which are produced by many plants, and some protozoans (very tiny one-celled organisms) that develop into new species which are without protective coverings: The group of Phylum Coniferophyta, or conifers, reproduce by means of gymnospores along the coast of California, U.S.A., and include junipers, firs, spruces, bristlecone pines, and the Sequoias.
gymnothesaurist (s) (noun), gymnothesaurists (pl)
Someone who collects pictures of partly clothed women or men; or both genders: Mr. Jones, a gymnothesaurist, always bought the newest fashion magazines, cut out the pictures of women with bikinis, shorts, or underwear and put them into his folder.
hydrogymnasium (s) (noun), hydrogymnasia (pl)
A therapeutic pool or special physical treatment or exercises that are done in a swimming pool or a special pool of water: Mrs. Smith had such bad back problems that her doctor told her to participate in a swimming class at the hydrogymnasium where the swimming teachers could help her train in water so she could recover from her aching back.
hydrogymnastic (adjective), more hydrogymnastic, most hydrogymnastic
Relating to exercises done in the water; such as, in a swimming pool: The hydrogymnastic training helped Linda improve the use of the muscles in her previously broken arm.
hydrogymnastics (pl) (noun) (plural used as a singular)
Therapeutic movements performed while immersed in water: The hydrogymnastics the physiotherapist showed Monroe were to be done as a regular exercise every day.
mechanogymnastics (noun) (a plural used as a singular)
Gymnastic conditioning done with mechanical devices; such as, a system of levers and pulleys designed to provide manipulation and exercises for the body and limbs: Tom does mechanogymnastics as often as possible in the local fitness studio in order to maintain a better physical status.

A related "unclothed; uncovered" word family: nudo-, nudi-.