From Latin intendere (to stretch toward), 'intend' preserves the metaphor of aiming at a target — stretching one's purpose toward a goal — while French took the same word to mean 'to understand.'
To have a course of action as one's purpose or plan; to mean something to have a particular meaning.
From Old French entendre (to direct one's attention, to understand), from Latin intendere (to stretch toward, to aim at), composed of in- (toward) and tendere (to stretch). The Latin tendere, from PIE *ten- (to stretch), is the source of an enormous word family including 'tend,' 'tender,' 'tension,' 'tent,' 'attention,' 'contend,' 'extend,' 'pretend,' and 'ostensible.' The original Latin meaning was physical: stretching a bow toward a target
In French, entendre means 'to hear' or 'to understand' — not 'to intend.' English and French took the same Latin word in completely different directions. The phrase 'double entendre' (a phrase with two meanings) preserves the French understanding sense in an English context, creating an etymological hybrid that is neither fully English nor properly French.