Charge density wave, or CDW, is a major form of order in solids. Its electronic origin was always associated with Fermi surfaces nesting. We here report a new CDW mechanism discovered in a 2H-structured transition metal dichalcogenide, where the exotic electronic structure conspires to realize the two essential ingredients of CDW in very anomalous ways. Namely, the CDW gap is only partially open, and charge density wavevector match is fulfilled through participation of states of the entire Brillouin zone, while the straight Fermi surface sections have secondary or negligible contributions. This new CDW mechanism resolves a long-standing mystery, and may be a general theme of ordering in systems in the strong coupling regime.