None of these words convey the nuance of "gist", wwh. A "gist" is not an adumbration, synopsis, abstract or precis. It is a dumbed down 'translation' of a techical article. It could be a synopsis or a precis but it is more than that. It seeks to interpret the work that is "gisted" in a manner that may not be technically accurate in order to make it comprehensible to a lay person. There is no flavor of that extended meaning in any of the alternatives proposed.