The word "most spilling" can have different synonyms depending on the context in which it is used. If it refers to liquid spills, synonyms can include "most leaking," "most overflowing," or "most splattering." In a figurative sense, "most spilling" can also be used to describe someone who is revealing too much information or emotion, in which case synonyms could be "most disclosing," "most open," or "most candid." In a negative sense, "most spilling" could indicate someone who is careless or accident-prone, and synonyms for this might include "most clumsy," "most awkward," or "most inept".