Other son securing flat for timely break (9)
I believe the answer is:
elevenses
'timely break' is the definition.
'elevenses' can be an answer for 'break' (I've seen this before). I am not sure about the 'timely' bit.
'other son securing flat' is the wordplay.
'other' becomes 'else' (similar in meaning).
'son' becomes 's' (genealogical abbreviation for son).
'securing' is an insertion indicator.
'flat' becomes 'even' (level).
'else'+'s'='elses'
'elses' enclosing 'even' is 'ELEVENSES'.
'for' acts as a link.
Can you help me to learn more?
(Other definitions for elevenses that I've seen before include "Mid-morning snacks" , "Mid-morning refreshment" , "Mid-morning snack" , "Morning tea or coffee break" , "Refreshments" .)