at length [æʔ ˈlɛŋθ] prepositional phrase3 •For a long time; extensively.He went on at great/long length about his supposed qualifications. •(formal, old-fashioned) At last, finally, eventually.She led us through the tunnels for some time, until at length we reached a small door in the rock. •(no longer used) In full; without omission or abbreviation.The proceedings of Congress are not given, since they are inserted at length in the "Congressional Globe;" but the principal bills are noticed under the date of their passage. — 1800
