Only

Part of speech: adjective (a.)

1. One alone; single; as, the only man present; his only occupation.

2. Alone in its class; by itself; not associated with others of the same class or kind; as, an only child.

3. Hence, figuratively: Alone, by reason of superiority; preëminent; chief. "Motley's the only wear." Shak.

Part of speech: adverb (adv.)

1. In one manner or degree; for one purpose alone; simply; merely; barely. And to be loved himself, needs only to be known. Dryden.

2. So and no otherwise; no other than; exclusively; solely; wholly. "She being only wicked." Beau. & Fl. Every imagination . . . of his heart was only evil. Gen. vi. 5.

3. Singly; without more; as, only-begotten.

4. Above all others; particularly. [Obs.] His most only elected mistress. Marston.

Part of speech: conjunction (conj.)

Save or except (that); -- an adversative used elliptically with or without that, and properly introducing a single fact or consideration. He might have seemed some secretary or clerk . . . only that his low, flat, unadorned cap . . . indicated that he belonged to the city. Sir W. Scott.