hairpin turn
US /ˈher.pɪn ˌtɜːrn/
UK /ˈher.pɪn ˌtɜːrn/

1.
tornante
a very sharp bend in a road, especially on a mountain, that doubles back on itself
:
•
The bus struggled to navigate the steep hairpin turn on the mountain road.
L'autobus faticava a percorrere il ripido tornante sulla strada di montagna.
•
Drivers must slow down significantly before a hairpin turn.
I conducenti devono rallentare significativamente prima di un tornante.