"Dhanus" means "bow" in Sanskrit. In the final position of this asana, the body takes the shape of a bow, drawn tight to shoot an arrow. The stretched arms and lower legs resemble the taut bowstring, while the trunk and thighs resemble the wooden part of the bow.
"Janu" means "knee" and "Siras" means "head" in Sanskrit. The head is made to rest on the knee in this posture, hence the name.
"Matsya" means "fish" in Sanskrit. If a person lies steadily on water in this posture, he can keep floating on it easily like a fish without the help of the hands and legs, as the name of the asana suggests.
"Padma" means "lotus" in Sanskrit. "Padmasana" means sitting in the "Lotus Pose". This posture is called Padmasana because the arrangement of the hands and feet resemble a lotus when seen from a distance. The two feet placed upon the opposite thigh resemble the leaves while the two hands placed one over the other resembles the lotus in full bloom.
"Paschima" means 'behind', 'back' or 'posterior' and 'Uttana' means to stretch out in Sanskrit. "Paschimotana" means stretching the posterior regions of the body.
"Supta" means "asleep" in Sanskrit. "Supta Vajrasana" is lying down supine in Vajrasana.
"Ushtra" means "camel" in Sanskrit.