What do you call the falling blocks in Tetris?

[clapiotis]

Tetris comes from
TETRAS (τετράς) = older Greek for a collection of four,
also TETRAD from Tetrad(a) (τετράδα) = modern Greek for a group of four
and TETRIS, TETRA, TETRAS & TETRAD come from the Greek number 4 which is TESSERA, TESSERIS, TETARTOS (τέσσερα, τέσσερις, τέταρτος).

note: if some letters are not readable it's because they're in Greek.