A complication to contend with (6)
I believe the answer is:
tangle
I believe this is a double definition.
'a complication' is the first definition.
(synonyms)
'contend with' is the second definition.
(thesaurus)
'to' acts as a link.
(Other definitions for tangle that I've seen before include "Enmesh, snarl up" , "Snarl or confused mass" , "Twist, snarl, knot" , "Snarl-up" , "Jumble" .)