1.A straining, stretching, or bending; the state of being strained; as, the intension of a musical string.
2.Increase of power or energy of any quality or thing; intenseness; fervency. "Sounds... likewise do rise and fall with the intension or remission of the wind."
3.(Logic & Metaph.) The collective attributes, qualities, or marks that make up a complex general notion; the comprehension, content, or connotation; opposed to extension, extent, or sphere. "This law is, that the intension of our knowledge is in the inverse ratio of its extension."