Pioneer father secures source of hieroglyphic discovery (10)
I believe the answer is:
pathfinder
'pioneer' is the definition.
(thesaurus)
'father secures source of hieroglyphic discovery' is the wordplay.
'father' becomes 'pater' (old-fashioned term for father**).
'secures' means one lot of letters goes inside another.
'source of' says to take the initial letters.
'discovery' becomes 'find' ('find' can be a synonym of 'discovery').
The initial letter of 'hieroglyphic' is 'h'.
'h'+'find'='hfind'
'pater' going around 'hfind' is 'PATHFINDER'.
(Other definitions for pathfinder that I've seen before include "One on recce" , "One who shows the way forward" , "Trailblazer far in, depth uncertain" , "radar device" , "Guide through unexplored territory" .)