crosshead
n
1 (Printing) a subsection or paragraph heading printed within the body of the text
2 a block or beam, usually restrained by sliding bearings in a reciprocating mechanism, esp. the junction piece between the piston rod and connecting rod of an engine
3 (Nautical) a bar fixed across the top of the rudder post to which the tiller is attached
4 a block, rod, or beam fixed at the head of any part of a mechanism