First woman among all to follow south-east geographical measuring base (3,5)
I believe the answer is:
sea level
'geographical measuring base' is the definition.
I can't tell whether this defines the answer.
'first woman among all to follow south-east' is the wordplay.
'first woman' becomes 'Eve' (first woman in the bible).
'among' is an insertion indicator.
'to follow' means one lot of letters go next to another.
'south east' becomes 'SE' (abbreviation).
'eve' placed within 'all' is 'alevel'.
'alevel' after 'se' is 'SEA-LEVEL'.
Can you help me to learn more?
(Other definitions for sea level that I've seen before include "Standard for measuring map heights" , "reference height?" , "0 feet?" , "From which altitudes are measured" , "Zero point for map heights" .)