WordWeb Online

1. Containing or using responses; alternating
   "responsive reading"
   - antiphonal
    
2. Readily reacting or replying to people or events or stimuli; showing emotion
   "children are often the quickest and most responsive members of the audience"
    
3. Reacting to a stimulus
   - reactive

See also: answering, respond, respondent, response, responsiveness, sensitive

Antonym: unresponsive