Holding back on shelter before a quarter past four (9)
I believe the answer is:
retentive
'holding back' is the definition.
(retentive means retaining or holding back)
'on shelter before a quarter past four' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'shelter before' becomes 'tent' (canvas shelter. I am not sure about the 'before' bit.).
'a quarter' becomes 'e'.
'past' says to put letters next to each other.
'four' becomes 'IV' (Roman numerals).
'e' after 'iv' is 'ive'.
're'+'tent'+'ive'='RETENTIVE'
(Other definitions for retentive that I've seen before include "Readily recalling" , "Able to hold in place" , "Not forgetful" , "(Of mind) able to remember" , "(Of memory) effective in holding information" .)