pen·tyl·ene·tet·ra·zol \ˌpentəˌlēnˈte.trəˌzȯl, -zōl\noun (-s) Etymology:pentamethylene-tetrazole : a white crystalline drug C6H10N4 used as a respiratory and circulatory stimulant and for producing a state of convulsion in treating certain mental disorders; pentamethylene-tetrazole