A harmonous pairing of body-conscious articles of clothing producing the effect of a unitard
or body suit.
A black spandex tanktop tucked into black leggings would be a two-nitard.
A leotard with leggings over it would be a two-nitard.
"I couldn't find the unitard for my interpretive dance class, so I threw together a two-nitard instead with my teal leotard and leggings."
"Her tunic was so sheer she had to wear a two-nitard under it."