Why is Brazil in called Brasil?

Brazil's name stems from pau brasil a Portuguese term for the brazilwood (caesalpinia echinata) which is native to Brazil and is considered endangered today.

Brazilwood's name came from its deep red ("brasa" in Portuguese) coloration, leading Portuguese colonists to name their new find Terra de Santa Cruz (Land of the Holy Cross) e Terra do Brasil (Land of Brazilwood) during their first encounters in 1500.

Later on, the name Brazil (Terra do Brasil) prevailed and became the official used for the Portuguese settlement in South America.