Street urchin and Waif

Street urchin noun - A child who spends most of his time in the streets especially in slum areas.

Waif and street urchin are semantically related In some cases you can use "Waif" instead a noun phrase "Street urchin".

Waif noun - A homeless child especially one forsaken or orphaned.

Street urchin and waif are semantically related in ragamuffin topic. You can use "Street urchin" instead a noun "Waif".