The term 'cause or enable to pass through' can be broken down into three crossword solutions: LET (3 letters), SEND (4 letters), and OSMOSE (6 letters). LET is a verb meaning to allow or permit something to happen. SEND is also a verb, meaning to cause something to go from one place to another. OSMOSE is a noun, referring to the process of a liquid or gas passing through a membrane. All three words refer to the idea of allowing something to pass through, either by permitting it, sending it, or allowing it to pass through a membrane.