Entry 1 sense Webster, 1913 Sisyphean /sīs'əfēʹən/ · Sis·y·phe·an · IPA /ˌsɪsəˈfiːən/ 01 a. Relating to Sisyphus; incessantly recurring; as, Sisyphean labors. 1. Relating to Sisyphus; incessantly recurring; as, Sisyphean labors.