Synonyms of rigorously

1 Syllable
straight, sic
2 Syllables
really, strictly, plainly, direct, simply, rightly, truly
3 Syllables
exactly, rowdily, correctly, directly, faithfully, stringently, actually, verbatim
4 Syllables
carefully, veritably, boisterously, difficultly, severely, unerringly, completely, precisely, literally, circumspectly, providently, literatim
5 Syllables
indisputably, undisputably, undeviatingly, unmistakably