bedfast means unable to leave one's bed, especially because of illness, weakness or obesity. Lexicurio rates it Rare gem — a strength score of 76 out of 100.
Etymology
From bed + fast.
adj
- Unable to leave one's bed, especially because of illness, weakness or obesity.“1796, Robert Burns, letter written to Mr. Cunningham, 7 July, 1796, in The Prose Works of Robert Burns; Containing his Letters and Correspondence, Newcastle-upon-Tyne: Mackenzie & Dent, 1819, p. 278 https://books.google.ca/books?id=gzYBAAAAQAAJ&printsec=frontcover#v=onepage&q&f=false
For these eight or ten months I have been ailing, sometimes bedfast and sometimes not; but these last three months ”
noun
- A joint or hook that attaches a bedrail to a headboard or footboard.
- One who is bedfast.