pulley, windless, wheel, block
樚 centers on mechanical devices for lifting or moving loads: a pulley, windlass, wheel, or block. The meanings all relate to simple machines that redirect force.
樚 combines 木 (wood) with 鹿, which likely contributes the sound ロク. The character probably originally referred to a wooden pulley or windlass.
A wooden (木) device shaped like a deer (鹿) with antlers that ropes wrap around: a pulley or windlass.
For ロク, imagine a wooden pulley creaking as it turns: the sound 'roke' (like 'roke' in 'broke') cues ロク.