孤身 literally combines 孤 (gū), meaning 'orphaned', 'lonely', or 'alone', and 身 (shēn), meaning 'body' or 'person'. Together, they form a compound adjective meaning 'alone' or 'unaccompanied', emphasizing the physical and emotional state of being without others—especially in situations where companionship or support is expected or needed. It carries a subtle connotation of vulnerability or quiet solemnity, not merely neutrality like 独自.

This word is commonly used in written Chinese and formal speech—for instance, describing someone traveling, working, or facing hardship without family or friends nearby. It often appears in literary, journalistic, or reflective contexts rather than casual conversation. While it can describe physical solitude, it frequently implies emotional isolation or resilience in adversity, making it richer than simple synonyms like 单独 or 独自.