Make the giant go up again (4)
I believe the answer is:
ogre
'make the giant' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'go up again' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'again' becomes 're' (prefix meaning 'again').
'go' back-to-front is 'og'.
'og'+'re'='OGRE'
Can you help me to learn more?
(Other definitions for ogre that I've seen before include "Fairy-tale creature" , "One making giant strides" , "Monstrous creature" , "Monster, troll" , "Wicked giant" .)