Turn cross, receiving hard riddle from one (6)
I believe the answer is:
sphinx
'riddle from one' is the definition.
(the sphinx gave out riddles in Greek myth)
'turn cross receiving hard' is the wordplay.
'turn' becomes 'spin' (spin is a kind of turn).
'cross' becomes 'x' (X is cross-shaped).
'receiving' indicates putting letters inside.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'spin'+'x'='spinx'
'spinx' going around 'h' is 'SPHINX'.
(Other definitions for sphinx that I've seen before include "Figure at Giza in Egypt" , "Egyptian atatue with lion's body and man's head" , "'Riddling monster, half-woman, half-lion (6)'" , "Egypt. monster statue" , "Egyptian 'lion-man'" .)