Chum
Bruce had always called Dick "chum." He had sometimes wondered about the uncommon name until one day he had a realization: Bruce was reinforcing that he was Dick's friend, partner, mentor, even family, but not his parent.
On the one hand, Dick had had wonderful parents and would never want them pushed from his life and replaced.
On the other, they were gone and Bruce was all he had in their place and the distance hurt.
In the end, he accepted Bruce was Bruce, a unique role.
(A returned Jason pointed out that "chum" was another word for shark bait.)
Yes, I know, "chum" wasn't that uncommon when the character of Dick Grayson was created, but my headcanon still stands that Bruce was trying to reassure Dick that he wasn't trying to replace his parents. Unfortunately, as usual, Bruce isn't that great with doing the right thing in personal relationships and bats don't talk and clear things up.
Also, I don't think Jason-Mr. "Robins-are-only-useful-to-the-Batman-as-bait" and "He-treats-us-like-we're-disposable-why-can't-the-others-see-that"-I don't think he could have passed up reminding anyone of the more common usage of the word "chum." He never lets anything go.