This is the 3084th most frequent Spanish word.
mina
"Mine" (a place for extracting minerals or explosives).
In this sentence, 'mina' refers to a mineral extraction site.
Esa mina de oro es muy peligrosa para los mineros.
That gold mine is very dangerous for the miners.
Here, 'mina' means an explosive device, specifically a naval mine.
Precaución, hay una mina bajo el agua.
Caution, there is a mine underwater.
In this case, 'mina' is used colloquially in Argentina as slang for a woman or a lady.