responsible (adj.)

"accountable for one's actions, answerable" to another, for an act performed or its consequences, 1640s, from obsolete French responsible (13c., Modern French responsable, as if from Latin *responsabilis), from Latin respons-, past-participle stem of respondere "respond, answer to, promise in return," from re- "back" (see re-) + spondere "to pledge" (see sponsor (n.)).

The meaning "reliable, trustworthy" is from 1690s. It retains the sense of "obligation" in the Latin verb. Related: Responsibly.

With regard to the legal use of the word, two conceptions are often confused — namely, that of the potential condition of being bound to answer or respond in case a wrong should occur, and that of the actual condition of being bound to respond because a wrong has occurred. For the first of these responsible is properly used, and for the second liable. [Century Dictionary]

Origin and meaning of responsible
Definitions of responsible

responsible (adj.)
being the agent or cause;
determined who was the responsible party
termites were responsible for the damage
Synonyms: responsible for
responsible (adj.)
worthy of or requiring responsibility or trust; or held accountable;
a responsible position
responsible journalism
a responsible adult
the captain is responsible for the ship's safety
the cabinet is responsible to the parliament
responsible (adj.)
having an acceptable credit rating;
a responsible borrower
Synonyms: creditworthy