Qat, Catha edulis has become synonymous with Yemen, as the phenomenon of Qat chewing in Yemen dates back hundreds of years in history. No social, cultural, or political gathering in the afternoon time can do without Qat. Afternoon time becomes the sign of Qat sessions and socialization. Despite Yemen's openness to other cultures and the recent revolution in all kinds of social media, Yemenis do not stop the habit of chewing Qat. The purpose of the present research work is to analyze 'Qat' as a linguistic sign consisting of a signifier and a signified to understand its various social, cultural, and political signifieds that give it the semiotic power to dominate all aspects of life in Yemen and to ground the coinage of many lexical items that are culturally specific to Qat culture and Yemeni dialects. The present paper uses semiotics as a research method in which it adopts Saussure's linguistic model of sign, signifier, and signified and Barthes' concepts of denotation and connotation. Semiotically, this paper shows that the Yemeni people are not addicted to Qat as a drug, as might be assumed by some foreigners who are not familiar with the sign system of Yemeni culture. The Yemeni people are addicted to Qat as a polysemous sign that is associated with values, norms, rituals, enjoyment, relationship, and socialization at the connotative level.