1More fully ram's head lady slipper, ram's head lady's slipper. A North American lady's slipper orchid, Cypripedium arietinum.
2Nautical = ram-head.
3In a narrowboat: the tiller or rudder post; the steering column of a motor.
Origin
Early 17th century (in an earlier sense). From the genitive of ram + head. So called on account of the resemblance of the various plants and objects so named to the head of a ram.