Definition of anchor stock in English:

anchor stock

Pronunciation /ˈaŋkə stɒk/

noun

historical Nautical
  • A crossbar at the top of an anchor, placed at right angles to the shank, and also to the plane of the arms, designed to cause one or other arm to strike the seabed.

    On striking the seabed, the anchor normally falls with the anchor stock parallel to the ground; when the cable is pulled, this causes one of the flukes to dig into the seabed and so hold the vessel in position.

Origin

Middle English; earliest use found in Mariner's Mirror. From anchor + stock.