Get set (4)
'get set' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for prep that I've seen before include "Homework (abbr.)" , "School work done outside lessons" , "Homework (abbrev.)" , "warm-up race" .)
(Other definitions for harden that I've seen before include "Anneal - solidify" , "Set; become tougher" , "Become less soft" , "Steel oneself" , "Temper, steel say" .)
'get set?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for thicken that I've seen before include "Become more dense (as plots do)" , "Make dense" , "Make less flowing" , "(Of a plot) become more complicated" , "Clot" .)