Hold and tie in knots (6)
I believe the answer is:
detain
'hold' is the definition.
(thesaurus)
'and tie in knots' is the wordplay.
'in knots' indicates anagramming the letters (I've seen this in other clues).
'and'+'tie'='andtie'
'andtie' with letters rearranged gives 'DETAIN'.
(Other definitions for detain that I've seen before include "Delay or take into custody" , "Hold in detention" , "Hang on to" , "Keep waiting or under restraint" , "put in jail" .)