Kibitzer can be defined as someone who gives unwanted or unsolicited advice or comments. There are several synonyms for this word, such as busybody, meddler, backseat driver, interloper, interferer, nosy parker, and intruder. A busybody is someone who eagerly intrudes on the affairs of others without being invited, whereas a meddler tends to interfere in the affairs of others without any permission. A backseat driver is someone who gives unwanted advice while sitting in the car, whereas an interloper is someone who gets involved in something without invitation. An interferer is someone who meddles in the affairs of others in an overbearing or intrusive way. A nosy parker is someone who pries into other people's business for no good reason, while an intruder is someone who enters a place without permission.