To large tree trunks. Sometimes used in spanish slang. Tronco meaning
Cock, dick, penis, ect.
When a friend is yawning and you pump your hand like if your shoving a cock
In his mouth. While his mouth is wide open and his eyes are closed
And you yell out tronco! Usually works better in front of other friends.
Tronco el centro de el árbol .
Ohh yeah" said the Mexican behind them!
Si no sabes que es un tronco eres un buey!