Broken–reed

the straight stalk of any of various tall grasses, especially of the genera Phragmites and Arundo, growing in marshy places.
any of the plants themselves.
such stalks or plants collectively.
anything made from such a stalk or from something similar, as an arrow.
Music.

a pastoral or rustic musical pipe made from a reed or from the hollow stalk of some other plant.
a small, flexible piece of cane or metal that, attached to the mouth of any of various wind instruments, is set into vibration by a stream of air and, in turn, sets into vibration the air column enclosed in the tube of the instrument.
reed instrument.

Textiles. the series of parallel strips of wires in a loom that force the weft up to the web and separate the threads of the warp.
an ancient unit of length, equal to 6 cubits. Ezek. 40:5.
to decorate with reed.
to thatch with or as if with reed.
to make vertical grooves on (the edge of a coin, medal, etc.).
a broken reed, a person or thing too frail or weak to be relied on for support:
Under stress he showed himself to be a broken reed.
Historical Examples

The Story of the Upper Canada Rebellion, Volume 1 John Charles Dent
George Muller of Bristol Arthur T. Pierson
Notes on the Book of Genesis Charles Henry Mackintosh
Great Men and Famous Women. Vol. 5 of 8 Various
K Mary Roberts Rinehart
Hide and Seek Wilkie Collins
The Bible, Douay-Rheims Version Various
Notes on the Book of Genesis Charles Henry Mackintosh
The Haunters & The Haunted Various
Helmet of Navarre Bertha Runkle

noun
any of various widely distributed tall grasses of the genus Phragmites, esp P. communis, that grow in swamps and shallow water and have jointed hollow stalks
the stalk, or stalks collectively, of any of these plants, esp as used for thatching
(music)

a thin piece of cane or metal inserted into the tubes of certain wind instruments, which sets in vibration the air column inside the tube
a wind instrument or organ pipe that sounds by means of a reed

one of the several vertical parallel wires on a loom that may be moved upwards to separate the warp threads
a small semicircular architectural moulding See also reeding
an ancient Hebrew unit of length equal to six cubits
an archaic word for arrow
broken reed, a weak, unreliable, or ineffectual person
verb (transitive)
to fashion into or supply with reeds or reeding
to thatch using reeds
noun
Sir Carol. 1906–76, English film director. His films include The Third Man (1949), An Outcast of the Islands (1951), and Oliver! (1968), for which he won an Oscar
Lou. born 1942, US rock singer, songwriter, and guitarist: member of the Velvet Underground (1965–70). His albums include Transformer (1972), Berlin (1973), Street Hassle (1978), New York (1989), Set the Twilight Reeling (1996), and The Raven (2003)
Walter. 1851–1902, US physician, who proved that yellow fever is transmitted by mosquitoes (1900)
n.
Reed
(rēd)
American physician and army surgeon who proved in 1900 that yellow fever was transmitted by the Aedes aegypti mosquito. His research led to the mosquito eradication programs carried out by William Gorgas that virtually eradicated yellow fever from Havana, Cuba, and from the Panama Canal Zone.

A weak or unreliable support, as in I’d counted on her to help, but she turned out to be a broken reed. The idea behind this idiom, first recorded about 1593, was already present in a mid-15th-century translation of a Latin tract, “Trust not nor lean not upon a windy reed.”
see: broken reed