Lying (or sometimes standing, or pinned) with your arms and legs stretched wide apart, so your body makes an X shape. The picture behind it is an eagle drawn with its wings and legs spread out — that shape is called a "spread eagle" and it appears on old flags and coins. Most often you hear it about someone lying face down or face up on a bed, on the floor, on the grass: "he was spreadeagled on the sofa", meaning he had flopped down and taken up the whole thing, arms and legs everywhere. It carries a feeling of no control — a person who is exhausted, drunk, asleep, knocked over, or dead. You would not use it for a person lying tidily. The other common use is the opposite of relaxed: someone held that way against their will, arms and legs pulled out and tied or pressed — spreadeagled against a wall by police, or spreadeagled on the ground after a fall. So the same word covers total collapse and being forcibly held; what the two share is that the body is open and helpless, not arranged by the person themselves. It is an adjective and comes after the verb be/lie, and it is written spreadeagled, spread-eagled, or spread eagled — all three are fine. The verb spreadeagle exists too but is much rarer. This is a written, descriptive word — a novel or a news report will use it; ordinary conversation usually just says "lying with his arms and legs out".

四肢張開躺著、大字型躺著（像老鷹展翅那樣手腳伸開）