Brief visit of offspring including day overseas (7)
I believe the answer is:
sojourn
'brief visit' is the definition.
'sojourn' can be an answer for 'visit' (I've seen this in another clue). I am unsure of the 'brief' bit.
'offspring including day overseas' is the wordplay.
'offspring' becomes 'son' (male offspring).
'including' indicates putting letters inside.
'day overseas' becomes 'jour' (I can't justify this - if you can you should give a lot more credence to this answer).
'son' enclosing 'jour' is 'SOJOURN'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for sojourn that I've seen before include "Stay temporarily" , "Relaxed, tolerant" , "Short stay" , "Reside temporarily" , "Temporary residence" .)