Habituate (8)
'habituate' is the definition.
(synonyms)
This is all the clue.
(Other definitions for accustom that I've seen before include "Inure" , "get used to" , "Make (someone) used to (something)" , "Familiarise" , "get one inured to" .)
'habituate' is the definition.
(inuring is a kind of habituating)
This is the entire clue.
(Other definitions for inure that I've seen before include "Come to accept" , "Steel" , "Harden against, make tough" , "Cause to become hardened to" , "To give experience" .)