what is the speed of an unladen swallow ?
The phrase unladen swallow is a reference to a popular line from the movie Monty Python and the Holy Grail and is not a scientifically recognized term. The speed of a swallow is around 17 meters per second (62 km/h), although this can vary depending on the species of swallow and the conditions.
Give me other references of the same movie and explain them literally, like you just did.