A homograph for a duck feather could be "quack," as it can refer to the sound a duck makes or to a type of medical professional.
Duck as in a bird. Duck as in to crouch down to avoid something.
duck
a quack.
Both. A homonym is a word that sounds the same as another but may be spelled differently. In either case, both words have different meanings. A homograph is a word that is spelled the same as another but has a different meaning. "Duck," meaning a waterfowl very capable in its early youth of imprinting upon a nurturer of another species, and "duck" meaning "Look out below!" fits both categories.
Yes, "down" is a homograph. It can be used as both an adverb, meaning in a lower or worse position, and as a noun, referring to soft, fluffy feathers.
Have is not a homograph.
Homograph
homograph homograph homograph homograph
obviously, it is homograph.
The homograph for a glass container is "jar," while the homograph for a rattle is "shake."
The homograph of "end" is "end" as in "the end of the movie." The homograph of "ship" is "ship" as in "a container ship." The homograph of "severe" is "severe" as in "a severe storm." The homograph of "harsh" is "harsh" as in "harsh criticism."