WordWeb Online

1. Capable of being perceived by the mind or senses
   "a perceptible limp"; "easily perceptible sounds"; "perceptible changes in behaviour"
    
2. Easily perceived by the senses or grasped by the mind
   "a perceptible sense of expectation in the court"
    
3. Easily seen or detected
   "he continued after a perceptible pause"
   - detectable

See also: audible, detectable, discernible, faint, hearable, noticeable, palpable, perceivable, perceive, perceptibility, perceptibly, recognisable [Brit], recognizable, seeable, sensible, tangible, visible, weak

Antonym: imperceptible