Essentially crave to get high in any way (2,3)
I believe the answer is:
at all
'in any way' is the definition.
(synonyms)
'essentially crave to get high' is the wordplay.
'essentially' means to look at the middle letters.
'to get' says to put letters next to each other.
'high' becomes 'tall' (similar in meaning).
The central letter of 'crave' is 'a'.
'a'+'tall'='AT ALL'
(Other definitions for at all that I've seen before include "Whatsoever" , "in any way" , "in any circumstances" .)