It's from Old French all right, but probably not because there was no existing word. Old English Translator[1] suggests geþanc (a bit similar to the modern German Gedanke) or the verb wénan, both of which can be confirmed by Bosworth & Toller's Anglo-Saxon Dictionary[2].
The Normans introduced French as the prestige language of England when they invaded, but Anglo-Saxons would have wanted to express the concept of imagination way earlier. If they had wanted to, they could have borrowed the word from Classical Latin imāginor without the 'help' of the Normans.
The Normans introduced French as the prestige language of England when they invaded, but Anglo-Saxons would have wanted to express the concept of imagination way earlier. If they had wanted to, they could have borrowed the word from Classical Latin imāginor without the 'help' of the Normans.
[1]: https://www.oldenglishtranslator.co.uk/index.htm
[2]: https://bosworthtoller.com/