Not unless; used to introduce a necessary condition.

Used other than figuratively or idiomatically: see if, only. / (idiomatic) I wish that; signifies a wish or desire for the present or the future.

An only child.

Alone in a category. / Singularly superior; the best. / Without sibling; without a sibling of the same gender. / (obsolete) Mere.

Without others or anything further; exclusively. / No more than; just. / As recently as. / (Britain) Used to express surprise or consternation at an action.

(informal) Under the condition that; but. / But; except.

(logic, mathematics) Is equivalent to; implies and is implied by; is true and false in the same cases as. / (by extension, informal) If, with added intensity

plural of only

plural of only

(obsolete) The state of being alone.