thom, 3D is a 2-letter bibliographic abbreviation for "in the same place", then the first letters of "empty rubbish", all inside what Americans sometimes call a "john" (with one letter extra).
Thom, in 3D “sweeper” is the definition, think football. Also you need to know how authors reference a series of quotes - full source reference the first time an then a Latin abbreviation for “in the same place” thereafter. Then “starts” has a common meaning in such clues, and I’m sure you can think of some toilets!
Can someone help me solve my missing piece. I am missing the final cell of the 3rd unclued across entry. I have all the rest, so am aware of what’s going on etc. I have scanned an exhaustive list and still nothing jumping out at me. Would appreciate a pointer. Thanks in advance