everlasting + -ly
everlastingly (comparative more everlastingly, superlative most everlastingly)
- In an everlasting manner; without end; forever.
- 1949, George Orwell, Nineteen Eighty-Four, Part Two, Chapter 9, 
- Their lives are dedicated to world conquest, but they also know that it is necessary that the war should continue everlastingly and without victory.
- perpetually; constantly
1909, Ford Madox Ford, The English Review, volume 2, page 130:
- They talk about education, everlastingly, as if it were a cure-all instead of a process for making unfit nations unfitter […]