Circumstantial meaning is a cover term for a °temporal circumstance, a °spatial circumstance, a °contingency circumstance, or a °manner circumstance.
"Circumstants" were introduced to grammatical terminology by Tesnière (1959), as opposed to "actants" (= arguments). The term was used for a syntactic function by Tesnière, corresponding to "adjunct". Here it is used for a set of semantic notions that are not necessarily coherent but are very often treated together by linguists.