In creche, loneliest place (7)
I believe the answer is:
echelon
'place' is the definition.
(thesaurus)
'in creche loneliest' is the wordplay.
'in' says the answer is hidden in the clue.
'ECHELON' can be found hidden inside 'creche loneliest'.
(Other definitions for echelon that I've seen before include "Body of troops arranged in a line" , "Military row formation" , "Military stepped formation" , "Leech on (anag.)" , "Level of command" .)