This is the 9830th most frequent Spanish word.
balsa
"Balsa" means "raft" in English.
Here, the word 'balsa' refers to a small, flat-bottomed boat, typically used to cross a body of water.
Ellos cruzaron el río en una balsa improvisada.
They crossed the river on an improvised raft.
In this case, 'balsa' refers to balsa wood, a lightweight wood often used in crafting or model-making.
Compré madera de balsa para construir la maqueta.
I bought balsa wood to build the model.
Here, 'balsas' refers to naturally formed masses of vegetation or wood floating on water.