Confused after son put on piece of tack (7)
I believe the answer is:
saddled
'put on piece of tack' is the definition.
(saddle is part of a horse tack)
'confused after son' is the wordplay.
'confused' becomes 'addled' (eg drug-addled).
'after' means one lot of letters go next to another.
'son' becomes 's' (genealogical abbreviation for son).
'addled' put after 's' is 'SADDLED'.
(Other definitions for saddled that I've seen before include "Encumbered" , "Having to put up (with) - ready to be ridden" , "Like a racehorse" , "Ready to ride" , "Horse might be" .)