Cries wildly about mid-January holiday (6)
I believe the answer is:
cruise
'holiday' is the definition.
(cruise is a type of holiday)
'cries wildly about mid-january' is the wordplay.
'wildly' indicates an anagram.
'about' is an insertion indicator.
'mid' indicates the central letters.
The central letter of 'january' is 'u'.
'cries' with letters rearranged gives 'crise'.
'crise' going around 'u' is 'CRUISE'.
(Other definitions for cruise that I've seen before include "Tom, say" , "Tour by ship" , "Ship holiday" , "Voyage for holiday makers" , "Sail on a ship" .)