Attested as early as the Jin dynasty (晉朝). Compare earlier form 楈枒 (OC *sŋa/sŋaʔ ŋraː/ŋraːs), 胥邪 (OC *sŋa/sŋaʔ ljaː/laː), 胥餘 (OC *sŋa/sŋaʔ la) (attested since Han dynasty).
This entry lacks etymological information. If you are familiar with the origin of this term, please add it to the page per etymology instructions. You can also discuss it at the Etymology scriptorium. Particularly: “時珍曰︰按稽含《南方草木狀》云︰相傳林邑王與越王有怨，使刺客乘其醉，取其首，懸於樹，化為椰子，其核猶有兩眼，故俗謂之越王頭，而其漿猶如酒也。此說雖謬，而俗傳以為口實。南人稱其君長為爺，則椰名蓋取於爺義也。相如《上林賦》作胥余，或作胥耶。”