Avocado is a one-seeded berry.

Iris Cohen schreef
How does it differ from a drupe, like peaches and cherries?

+ + +
He just explained that. In avocado the tissue arising out of the carpel that
is closest to the seed is fleshy. An avocado consists of exocarp, mesocarp
and seed.

In a drupe the seed is inside a 'stone' which means that the tissue arising
out of the carpel closest to the seed is quite hard. A drupe consists of
exocarp, mesocarp, endocarp and seed.
PvR