We call families of words those that are part of a root and that have been created by derivation processes, for example: casa, casita, casero, caserón, casucha … But we also use that expression to talk about different words that coexist. They are used in the same context.

Find the odd man out in these groups of things.

Hotel, albergue, playa, hostal.
Hotel hostel, beach, guesthouse.

Museo, plaza, monumento, montaña.
Museum, square, monument, mountain.

Naturaleza, camping, avión, campo.
Nature, campground, plane, field.

Verano, coche, tren, taxi.
Summer, car, train, taxi.

Bosque, selva, desierto, brújula.
Wood, forest, desert, compass.