D defs.my
Entry 1 sense Webster, 1913

Sea legs

/sē lĕgz/ · Sea· legs · IPA
01 Legs able to maintain their possessor upright in stormy weather at sea, that is, ability to stand or walk steadily on deck when a vessel is…
  1. 1.
    Legs able to maintain their possessor upright in stormy weather at sea, that is, ability to stand or walk steadily on deck when a vessel is rolling or pitching in a rough sea.[Sailor's Cant]