Definition
A landlubber is a nautical term for someone who is unfamiliar with the sea or ships, or who is clumsy and awkward on a boat. It's often used in a humorous or slightly derogatory way to describe someone who is new to sailing or doesn't have their 'sea legs' yet. Think of it as the opposite of a seasoned sailor. It's like calling someone a newbie when they're trying to learn a new skill. It is basically a synonym for a greenhorn on the sea!