rasanā (Sanskrit). In tantric mystical physiology, the channel (nāḍī) to the left of the avadhūti or central channel, which starts in the left-hand nostril and terminates at the genitals. It is visualized as a fine white tube and the energy (vāyu) flowing through it is thought to generate the objective aspect of cognition. Like the lalanā, the right-hand channel, it is believed to coil around the avadhūti and form knots at the mystic centres (cakras) of the navel, heart, throat, and the crown of the head.

A Dictionary of Buddhism, Oxford University Press, 2003, 2004 (which is available in electronic version from answer.com)

rasanā : [f.] a girdle for women. || see mekhalā.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]