Finally down, wearing the tie, dressed for big birthday? (9)
I believe the answer is:
ninetieth
'big birthday?' is the definition.
'ninetieth' can be an answer for 'birthday?' (I've seen this before). I am unsure of the 'big' bit.
'finally down wearing the tie dressed' is the wordplay.
'finally' suggests the final letters.
'wearing' becomes 'in' (you are 'in' the clothes you're wearing).
'dressed' indicates an anagram ('dress' can mean 'prepare').
The last letter of 'down' is 'n'.
'the'+'tie'='thetie'
'thetie' is an anagram of 'etieth'.
'n'+'in'+'etieth'='NINETIETH'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for ninetieth that I've seen before include "An anniversary" , "Birthday" , "in the last minute?" , "ordinal" .)