only

(noun): An only child.
(adjective): Alone in a category.
(adjective): Singularly superior; the best.
(adjective): Without sibling; without a sibling of the same gender.
(adjective): Mere.
(adverb): Without others or anything further; exclusively.
(adverb): No more than; just.
(adverb): As recently as.
(adverb): Used to express surprise or consternation at an action.
(adverb): Introduces a disappointing or surprising outcome that renders futile something previously mentioned. See also only to, only for.
(adverb): Above all others; particularly.
(conjunction): Under the condition that; but.
(conjunction): But; except.