Source : Webster's Revised Unabridged Dictionary (1913)

Only \On"ly\, adv. [See {Only}, a.]
   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.

Only \On"ly\, a. [OE. only, anly, onlich, AS. [=a]nlic, i.e.,
   onelike. See {One}, {and Like}, 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;
      pre["e]minent; chief. ``Motley's the only wear.'' --Shak.

Only \On"ly\, 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.

Source : WordNet®

only
     adj 1: being the only one; single and isolated from others; "the
            lone doctor in the entire county"; "a lonesome pine";
            "an only child"; "the sole heir"; "the sole example";
            "a solitary instance of cowardice"; "a solitary speck
            in the sky" [syn: {lone(a)}, {lonesome(a)}, {only(a)},
             {sole(a)}, {solitary(a)}]
     2: exclusive of anyone or anything else; "she alone believed
        him"; "cannot live by bread alone"; "I'll have this car
        and this car only" [syn: {alone(p)}]

only
     adv 1: and nothing more; "I was merely asking"; "it is simply a
            matter of time"; "just a scratch"; "he was only a
            child"; "hopes that last but a moment" [syn: {merely},
             {simply}, {just}, {but}]
     2: without any others being included or involved; "was entirely
        to blame"; "a school devoted entirely to the needs of
        problem children"; "he works for Mr. Smith exclusively";
        "did it solely for money"; "the burden of proof rests on
        the prosecution alone"; "a privilege granted only to him"
        [syn: {entirely}, {exclusively}, {solely}, {alone}]
     3: with nevertheless the final result; "He arrived only to find
        his wife dead"; "We won only to lose again in the next
        round"
     4: in the final outcome; "These news will only make you more
        upset"
     5: except that; "It was the same story; only this time she came
        out better"
     6: never except when; "call me only if your cold gets worse"
        [syn: {only if}, {only when}]
     7: as recently as; "I spoke to him only an hour ago"