At bay, new worker has engagement (8)
I believe the answer is:
covenant
'engagement' is the definition.
(thesaurus)
'at bay new worker' is the wordplay.
'at' says to put letters next to each other.
'bay' becomes 'cove' (I've seen this before).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'worker' becomes 'ant' (worker is a type of ant).
'cove' next to 'n' is 'coven'.
'coven'+'ant'='COVENANT'
'has' acts as a link.
(Other definitions for covenant that I've seen before include "Formal agreement of contract" , "Legal agreement" , "Signed agreement between two or more to do something" , "Binding agreement between two parties" , "Formal binding agreement" .)