Support an attempt to back a horse to come first (6)
I believe the answer is:
gantry
'support an' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
I also know that 'support' relates to this answer.
'attempt to back a horse to come first' is the wordplay.
'attempt' becomes 'try' (synonyms).
'to back' shows that the letters should be reversed in order.
'a horse' becomes 'nag' (term for an old horse).
'to come first' means one lot of letters go next to another.
'nag' written backwards gives 'gan'.
'try' after 'gan' is 'GANTRY'.
Can you help me to learn more?
(Other definitions for gantry that I've seen before include "Bridge-like overhead structure, supporting cameras etc" , "Bridge-like framework for supporting cranes" , "Support for, eg, crane" , "Overhead structure supporting equipment" , "platform" .)