only

noun

An only child.

1. Alone in a category.

   He is the only doctor for miles.

2. Singularly superior; the best.
3. Without sibling; without a sibling of the same gender.

   He is their only son, in fact, an only child.

4. Mere.

1. Without others or anything further; exclusively.

   My heart is hers, and hers only.

2. No more than; just.

   If there were only one more ticket!

3. As recently as.

   He left only moments ago.

4. Used to express surprise or consternation at an action.

   She's only gone and run off with the milkman!

5. Introduces a disappointing or surprising outcome that renders futile something previously mentioned. See also only to, only for.

   I helped him out only for him to betray me.

6. Above all others; particularly.

1. Under the condition that; but.

   You're welcome to borrow my bicycle, only please take care of it.

2. But; except.

   I would enjoy running, only I have this broken leg.