The term 'MISCHIEVOUS WAIF' is composed of two words, the first being 'MISCHIEVOUS' and the second being 'URCHIN'. The word 'MISCHIEVOUS' is an adjective that describes someone who is prone to misbehaving or causing trouble. It is often used to describe children who are naughty or disobedient. The word 'URCHIN' is a noun that refers to a young street child or homeless person. Together, the two words form the phrase 'MISCHIEVOUS WAIF', which is used to describe a young person who is both MISCHIEVOUS and homeless.