Definition
"Hypersensitised" is simply an alternative spelling of "hypersensitized," primarily used in British English. It carries the same meaning: describing a state of increased sensitivity or reactivity to a particular substance or stimulus, often as a result of prior exposure. Think of it as the same word, just with a different spelling convention. So, like before, it is similar to being hypersensitive but implies a process led to the increased sensitivity. Like a film that's been treated to make it more sensitive to light ๐๏ธ.