Wheelchair safety mechanism (5)
I believe the answer is:
brake
(Other definitions for brake that I've seen before include "Slower" , "Decelerate" , "Cause to slow down" , "Slowing-down device" , "Device for slowing vehicle" .)
I believe the answer is:
brake
(Other definitions for brake that I've seen before include "Slower" , "Decelerate" , "Cause to slow down" , "Slowing-down device" , "Device for slowing vehicle" .)