A layman’s definition:  A dictionary offers “answerable” and “responsible” as synonyms for the word liable.  So being liable means being responsible for one’s actions – particularly when those actions cause harm to the another person.

Accidental or deliberate?  Tom is angry at Dick and punches Dick in the nose; Tom is “answerable” to Dick for that deliberate act.  While driving to the hospital to get his nose fixed, the car in front of Dick slows abruptly and Dick avoids a collision by changing lanes.  Dick failed to see Harry’s car in the lane he changed into.  Dick is “responsible” for the dent he unintentionally put in Harry’s new car.  In the pure sense of liability, it makes no difference whether an act is deliberate or accidental.  However in the sense of liability insurance, we may find that it does.  Read on.