Source : Webster's Revised Unabridged Dictionary (1913)

Timely \Time"ly\, a. [Compar. {Timelier}; superl. {Timeliest}.]
   1. Being or occurring in good time; sufficiently early;
      seasonable. ``The timely dew of sleep.'' --Milton.

   2. Keeping time or measure. --Spenser.

Source : WordNet®

timely
     adj 1: before a time limit expires; "the timely filing of his
            income tax return"
     2: done or happening at the appropriate or proper time; "a
        timely warning"; "with timely treatment the patient has a
        good chance of recovery"; "a seasonable time for
        discussion"; "the book's publication was well timed" [syn:
         {seasonable}, {well-timed(a)}, {well timed(p)}]
     adv : at an opportune time; "your letter arrived apropos" [syn: {seasonably},
            {well-timed}, {apropos}]
     [also: {timeliest}, {timelier}]

timelier
     See {timely}