Besides the main categories of meat, dairy, and pareve (non-meat, non-dairy) foods, two special subcategories of pareve foods are relevant to halacha (e.g. Yore Dea 93): pareve food cooked using clean meat utensils, and pareve food cooked using clean dairy utensils.
In America, those foods are colloquially known as "[meat/dairy/other words] kelim" or "[meat/dairy/other words] equipment". (Kelim means "receptacles".) In fact, what's probably the largest kashruth supervisory agency in the United States, the Orthodox Union, has in the past allowed products to have a "DE" certification mark, signifying "dairy equipment". And this all makes a lot of sense: the phrase "dairy equipment", or "meat kelim", or the like, refers, as a metonym, to the food that was prepared on such equipment.
In Israel, on the other hand, those foods are called "b'chezkas [b'sari/chalavi]", "with/in a chazaka of [meat/dairy]". In its normal uses in halacha, "chazaka" is probably best translated "status": it refers to the state that something or someone is in or can be presumed to be in absent evidence of a change of state. So these foods are called "with a status of meat" or "with a presumption of dairy" or the like. Why? They're not meat or dairy themselves; nor is there any halachic chazaka (that I know of) that says that they are. Where does this "b'chezkas" wording come from and why is this state referred to by this terminology?