1. what or which person or persons: who left?
2. used as a relative pronoun to introduce a clause when the antecedent is a person or persons or one to whom personality is attributed: the visitor who came yesterday; our child, who is gifted; informed sources who denied the story.
3. the person or persons that; whoever: who believes that will believe anything.

1. what person or people; which person or people (used in a direct or indirect question).
2. the person or people that.
3. A person under discussion; a question of which person.

1. originally, an interrogative pronoun, later, a relative pronoun also; -- used always substantively, and either as singular or plural. see the note under what, pron., 1. as interrogative pronouns, who and whom ask the question: what or which person or persons? who and whom, as relative pronouns (in the sense of that), are properly used of persons (corresponding to which, as applied to things), but are sometimes, less properly and now rarely, used of animals, plants, etc. who and whom, as compound relatives, are also used especially of persons, meaning the person that; the persons that; the one that; whosoever.
2. one; any; one.

1. denoting a personal object of inquiry: what man or woman? what person?
2. in certain special uses who appears
3. inquiring as to the character, origin, or status of a person: as, who is this man? (that is, what are his antecedents, his social standing, etc.); who are we (what sort of persons are we) that we should condemn him?
4. in exclamatory sentences, interrogative in form but expecting or admitting no reply: as, who would ever have suspected it!
5. introducing a dependent clause, and noting as antecedent a subject, object, or other factor, expressed or understood, in a clause actually or logically preceding.
6. the antecedent is sometimes omitted, being implied in the pronoun, which is in this case usually called a compound relative.
7. A clause dependent in form, but adding a distinct idea. here the relative force is almost entirely lost, who becoming equivalent to and with a demonstrative pronoun.
8. with reference to gender, who originally noted a masculine or feminine antecedent, whether human, animate, or other, the neuter being what; and whose, the possessive (genitive)of who, was also that of what, and is still correctly used of a neuter antecedent (see what). moreover, before the appearance of the possessive its, whose place was filled by the neuter his (see he, I., C. ), not only were neuter objects designated in the two other cases by he and him, but who and whom were sometimes substituted for that as the nominative and objective of the neuter relative (see the quotation from Puttenham). in modern use, however, who and whom are applied regularly to persons, frequently to animals, and sometimes even to inanimate things when represented with some of the attributes of humanity, as in personification or vivid description.
9. with reference to the nature of its antecedent, who may note
10. a particular or determinate person or thing (see ); or
11. an indefinite antecedent, in which case who has the force of whoso, whosoever, or whoever, and is called an indefinite relative. its antecedent may be expressed, or it may be a compound relative.
12.

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