Rigorous
Meticulous
Synonyms Meticulous, conscientious, diligent, ultra-careful, painstaking, precise, correct, studious, mathematical, perfectionist, particular, strict, fastidious, finicky, demanding, pedantic, pernickety, nice, laborious, punctilious, careful, attentive, scrupulous, exact, accurate, thorough, exhaustive, detailed, methodical, religious, fussy, hair-splitting, finical, exacting, nitpicking, persnickety, and overnice.
Strict
Synonyms Strict, stern, austere, tough, harsh, cruel, relentless, inflexible, despotic, intransigent, demanding, severe, stringent, spartan, hard, rigid, savage, unsparing, authoritarian, draconian, uncompromising, and exacting.
Harsh
Example Sentences
The training program is very rigorous.
They follow rigorous safety procedures always.
Her research requires rigorous analysis techniques.
The curriculum is rigorous and challenging.