means,
Excited; glowing; very warm; lively; full of spirit; eager; passionate; zealous. (From a Latin word meaning, "To be hot; to boil; to glow".)

Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: Being born again, not of corruptible seed, but of incorruptible, by the Word of God, which liveth and abideth forever.
1 Peter 1:22 & 23