A sexual position where one participant is penetrated from behind by the other, while the penetrated partner has their arms are held behind them (as opposed to with their hands on the ground, supporting their weight). In this position, the penetrating partner must support the weight of the penetrated, who leans out and forward, resembling a figurehead, or carved wooden decoration located on the prow of old ships.
Sam: Look, this guy just messaged me on Fitocracy!
Christina: Look at those arms!
Sam: It's kinda scary actually.
Christina: He totally wants to figurehead you.