1.Definition: being the agent or cause
"Determined who was the responsible party", "Termites were responsible for the damage"
2.Definition: having an acceptable credit rating
"A responsible borrower"
3.Definition: worthy of or requiring responsibility or trust; or held accountable
"A responsible adult", "Responsible journalism", "A responsible position", "The captain is responsible for the ship's safety", "The cabinet is responsible to the parliament"