Books about American started in a mess (7)
I believe the answer is:
tousled
'books about american started in a mess' is the definition.
I can't tell whether this defines the answer.
'books about american started' is the wordplay.
'books' becomes 'OT' (abbreviation for Old Testament).
'about' shows that the letters should be reversed in order.
'american' becomes 'US' (abbreviation for United States).
'started' becomes 'led' (I've seen this in another clue).
'ot' back-to-front is 'to'.
'to'+'us'+'led'='TOUSLED'
Can you help me to learn more?
(Other definitions for tousled that I've seen before include "Of hair, untidy in loudest way" , "Dishevelled" , "Of hair, untidy and tangled" , "In disarray, hair perhaps" , "Mussed up" .)