Together, 光棍 (guānggùn) means “bare stick,” a vivid slang term for a bachelor or an unmarried man, and by extension, any single person. Adding 节 (jié) makes it 光棍节 (Guānggùn jié), or “Singles' Festival.”
The connotation is generally positive and exciting due to the shopping frenzy. The slight undertone of loneliness from its original meaning has become more of a running joke than a serious sentiment.