10D Take the word for 'having spouse' Remove the abbreviation for arranged and replace with another word for single, this provides the extra letter, definition = rich 12D Current - think electrical, gives the extra letter, Russian ruler (the terrible) and abbreviation for special. 15D Unruly youths, the usual crossword answer for these, plus abbreviation for gunners - again the usual one, turn as in take a turn, have a ??, here is the extra letter, def. =ground 40A think of young fish, first of this word is extra letter.