perennial (adjective) perennial: enduring, perpetual
Sinonime: absolutely, actually, admittedly, as a matter of fact, assuredly, authentically, beyond doubt, categorically, certainly, de facto, easily, for real, genuinely, honestly, in actuality, in effect, in fact, in point of fact, in reality, indeed, indubitably, legitimately, literally, no ifs ands or buts, nothing else but, of course, positively, precisely, surely, truly, undoubtedly, unmistakably, unquestionably, verily, well
Antonime: doubtfully