keel

• 指船或小船的底部中央纵向结构构件，即龙骨；也指鸟类胸骨上的类似隆起（龙骨突），或任何表面上突出的脊状隆起。

A noun referring to a longitudinal structural member along the bottom of a ship or boat, or a similar ridge on the breastbone of flying birds, or any ridge projecting from a surface.

1. ridge or projectionB2formaltechnical

   A natural or artificial ridge that resembles the structure of a ship's keel, often found in anatomy, geology, or design.

   隆起或突出

   • The fossil had a prominent keel along its back.
   • The mechanical part featured a central keel for reinforcement.
   • In some plants, the leaf has a keel-shaped midrib.

   同义词carinacrestridgespine

2. bird's breastbone keelC1formalscientific

   The median ridge on the sternum (breastbone) of flying birds to which flight muscles attach.

   龙骨突

   • The ornithologist pointed out the well-developed keel on the eagle's skeleton.
   • Flightless birds like ostriches have a reduced or absent keel.
   • The keel provides a stable anchor for powerful wing muscles.

   同义词carina

3. ship's keelB2formaltechnical

   The main longitudinal structural element of a ship's hull, running from bow to stern, providing stability and strength.

   船龙骨

   • The ship's keel was laid down in the dry dock.
   • Damage to the keel can cause serious instability at sea.
   • Modern vessels often have a bulbous keel for better hydrodynamics.

• 动词，指翻倒、倾覆，常用于航海语境中表示船只翻覆；也用于比喻义，表示摔倒、崩溃或垮掉。

A verb meaning to turn over or capsize, typically used in nautical contexts; also used figuratively to mean to collapse or fall down.

1. Stagger or swayB2informal

   To walk or move unsteadily, as if about to fall or lose control.

   摇晃

   • He keeled over after drinking too much.
   • The boxer keeled from the punch.
   • She keeled sideways, clutching her head.

   同义词lurchreelstaggerswaytotterwobble

   反义词balancesteady

短语动词变体keel over