Title says it all.
Other than key-value pair
That is to say, what are your criteria? Are you hoping for a single word? I suppose you could use "definition." Or "entry," short for "dictionary entry."
But "key-value pair" really packs in a lot of information.
In Smalltalk we are used to calling a key-value pair an association.
Oh right! In Lisp too. Why didn't I think of that? I always think "association list" but I never really have occasion to talk about one element of the list.
hehe, in Smalltalk there's actually an Association class, so it's not something you have to remember