Firefly rhymes with:
butterfly, hoverfly, botfly, butterfly, gadfly, hoverfly, shoofly, alkali, alveoli, botfly, butterfly, eagleye, gadfly, hoverfly, lorelei, maglaj, multiply, nicolae, nikolai, seelye, shoofly, stimuli, walleye
Firefly sounds like:
favorable, favorably, fearful, fireball, foreplay, frable, fravel, freefall, friebel