rockshaft

[ rok-shaft, -shahft ]
/ ˈrɒkˌʃæft, -ˌʃɑft /

noun Machinery.

an oscillating shaft.

Origin of rockshaft

First recorded in 1870–75; rock2 + shaft

British Dictionary definitions for rockshaft

rockshaft
/ (ˈrɒkˌʃɑːft) /

noun

a shaft that rotates backwards and forwards rather than continuously, esp one used in the valve gear of a steam engine