The most common and most likely answer to this crossword clue is the 8 plus 7 letter word AÂ STITCH INÂ TIME
I've seen this crossword clue in The Guardian
A
Â
S
T
I
T
C
H
I
N
Â
T
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M
E
Buddy explains!
The straight part
We know that "What man in essence and woman in effect both have proverbially to solve the problem immediately" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case what man in essence and woman in effect both have proverbially to solve the problem immediately = a stitch in time.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.