### Clue: F-form s-swap? (3,6)
### Answer: SEX CHANGE 
 ### Explanation: Definition: F-form s-swap
 The clue is to be read as "f" for "m"s swap, ie. [abbrev. for "female"] replacing [abbrev. for "male"], ie. a SEX CHANGE. Best clue I've seen for a long time. By coincidence, all but one of the changes are in the initial letter of the answer, so I got the "CHANGE" bit early, but thought it was something to do with changing the initial letters. Only after the last one (22 across) did the light bulb go on. Doh!