Many were carried away by it and lost their heads (7)
I believe the answer is:
tumbrel
'many were carried away' is the definition.
I can't judge whether this defines the answer.
'it and lost their heads' is the wordplay.
'it' becomes ''t' (abbreviation. e.g. in 'tis).
'and' means one lot of letters go next to another.
'lost' becomes 'l' (abbreviation in sporting league tables).
'their' becomes 'umbre' (I can't justify this - if you can you should believe this answer much more).
'heads' says to put letters next to each other (some letters go ahead of others).
'l' after 'umbre' is 'umbrel'.
't' next to 'umbrel' is 'TUMBREL'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for tumbrel that I've seen before include "Cart in which aristocrats were taken to guillotine" , "transport to block" , "Condemned transport" , "Cart to take the aristocracy to the guillotine" , "Guillotine conveyance" .)