adjective
Definition: Referring to something that is one in number, unique, or remarkable; not plural or common.
Example: Her singular talent for music set her apart from her peers.
noun
Definition: A term used in grammar to refer to a word or form that indicates one person, thing, or concept, as opposed to plural forms that indicate more than one.
Example: In English, the word 'cat' is in the singular form, while 'cats' is plural.