intension
Intensity or the act of becoming intense.
uncountable
Sounds […] likewise do rise and fall with the intension or remission of the wind.
Intensification.
countable, uncountable
Any property or quality connoted by a word, phrase or other symbol, contrasted with actual instances in the real world to which the term applies.
countable
'Is a plant', 'has a trunk', 'has leaves' are intensions of the concept tree. Its extension is the set of all trees existing in the real world.
A straining, stretching, or bending; the state of being strained.
countable, dated
the intension of a musical string
Where it comes from
From Latin intēnsiō (“straining, effort; intensifying”), from intēnsus (“stretched”), perfect passive participle of intendō (“strain or stretch toward”).
Adapted from the Wiktionary entry intension (CC BY-SA 4.0).