Placidly rhymes with:
admittedly, assertedly, candidly, discontentedly, evenhandedly, good-heartedly, guardedly, handedly, heartedly, heatedly, mindedly, pointedly, purportedly, repeatedly, reputedly, rigidly, singlehandedly, unabashedly, undoubtedly, unexpectedly, unprecedentedly, validly, wholeheartedly, wickedly, wretchedly