What is Bill Chamber?

Legal Definition
The Bill Chamber was formerly a court of Scotland, often considered as part of the Court of Session but in fact separate from it. It dealt with petitions for suspension (appeal), interdict, sequestrations etc., and was the approximate equivalent to sittings in camera (in chambers) in American or English law.

The Bill Chamber was "under the same roof" as the Court of Session, but was a separate court or jurisdiction. Its history and function were discussed in the report of the Royal Commission on the Court of Session and the Office of Sheriff Principal (1927) which concluded "the usefulness of the Bill Chamber as a Court separate from the Court of Session no longer exists" and it was thus abolished by the Administration of Justice (Scotland) Act 1933.

Some of its processes are now carried out by the Accountant in Bankruptcy.
-- Wikipedia
Legal Definition
In Scotch law. A department of the court of session in which petitions for suspension, interdict, etc., are entertained. It is equivalent to sittings in chambers in the English and American practice. Paters. Comp.
-- Black's Law Dictionary
Legal Definition
A department of the Scotch court of session.
-- Ballentine's Law Dictionary