callejón
alley
calle
street
+
-ón
augmentative suffix
Callejón means alley and can be thought of as calle0 (street0) + -ón1, where -ón1 suggests a more significant or distinct type of street.
noun
- alleyA narrow street or alleyEl gato se escondió en un callejón oscuro. // The cat hid in a dark alley.