tag‧a‧long /ˈtæɡəlɒŋ $ -lɒːŋ/
noun [countable]1. British English something that is attached to and pulled behind something else:
The tagalong attaches to an adult’s bicycle.2. someone who goes somewhere with someone else:
We were tagalongs on my parents’ vacations. [TahlilGaran] Dictionary of Contemporary English ▲