Tapas (n.) is creation by self-incubation: Prajapati "heated himself with his own heat," brooded his own brooding, became his own womb and hatched forth the world.
Tapas (n.) is self-brooding: meditation without content, in which libido is fed to one's own self like incubating heat until inside and outside become one — 'that art thou'.
Tapas (n.) is yoga's self-incubation, the brooding heat of meditation — the same hidden fire in the whale's belly whose aim is transformation and resurrection.
Tapas (n.) is the Sanskrit "self-brooding," the self-knowledge that the circular movement amounts to morally, activating the light and dark forces of human nature.
Tapas (n.) means incubation by "self-heating," the introversion in which an unconscious content is brooded over and digested, all ties to the outside cut, until it is sublimated into conscious discrimination.