A backseat refers to the second row of seats in a car or other vehicle. You know, the ones behind the front seats where passengers sit.
When we talk about "riding in the backseat," it usually means that someone else is driving and you're along for the ride. This phrase is often used when friends are going somewhere together, like to school or work, and one person is giving another a lift. For example, if you ask your friend if they can drive you home from the party, and they say "yeah, but I'll have to drop off my other friend first," that means you'll be riding in their backseat while he stops by his friend's house along the way. Sometimes, people use this phrase when talking about kids being driven around by their parents - "my kid is always arguing with her mom from the backseat."
Alternative spelling of back seat.
