Another word for rigor
rigidity, stiffness, inflexibility, hardness, sternness, harshness, hardship, difficulty, austerity, severity, strictness, stringency, inexorability, obduracy, exactitude, preciseness, precision, intolerance, obstinacy, freedom from deviation, uncompromisingness, inclemency, tenacity, traditionalism, conventionalism, relentlessness, rigorousness; see also stubbornness.
Another word for rigornoun
The fact or condition of being rigorous and unsparing:austerity, hardness, harshness, rigidity, rigorousness, severity, sternness, strictness, stringency, toughness. See easy
Something that obstructs progress and requires great effort to overcome:asperity, difficulty, hardship, vicissitude (often used in plural). Idioms: a hard (or tough) nut to crack, a hard (or tough) row to hoe, heavy sledding. See easy