Even in their original nation, the word 'Tantra' is an excellent example of something that doesn't have a very clear definition.
The Tantras are a collection of religious literature with varying degrees of complexity. Some of them, such as the Tantra of the Great Liberation, are high poetry.
Others are simply a few pages long, are written in a clumsy manner, and aren't much different from the European Grimoires. Tantra, in our opinion, is a comprehensive term that denotes activity. It denotes that theory and practice are in sync. Tantra has been compared to a shuttle that directs the threads to produce a whole fabric, just how Yoga has been compared to a yoke to which oxen have been tied to drive a cart.
You may also want to read more about Tantra and Healing here.