Duck as in a bird. Duck as in to crouch down to avoid something.
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
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
Is car a 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."