Middle English a hollow moldingpossibly from Middle English casechest, framecase2
American Heritage Dictionary of the English Language, 5th Edition
Casement Sentence Examples
After the outbreak of the World War Casement went to the United States, whence he wrote in Oct.
Redmond Howard, Sir Roger Casement: a Character Sketch without Prejudice (1916).
"Princess, my dear, there's someone driving up the avenue!" she said, holding the casement and not closing it.
This despatch failed to evoke any response from the powers, with the single exception of Turkey, but the public agitation against the Congo State regime continued to grow in force, being greatly strengthened by the publication in February 1904 of a report by Mr Roger Casement, then British consul at Boma, on a journey which he had made through the middle Congo region in 1903 (described as the "Upper" Congo in the report).
Casement, who with two companions had landed in a collapsible boat at Banna, was arrested on the 24th in a ruined fort which afterwards became a place of pilgrimage for Sinn Fein Irishmen.