Synonyms for Eternally:

adv

durably (adverb)
perennially, perpetually, Endurably, incessantly, interminably, Durably, lastingly, everlastingly, lengthily.
infinitely (adverb)
illimitably, innumerably, boundlessly, limitlessly, perpetually, inexhaustibly, infinitely, incalculably, Timelessly, everlastingly, unboundedly, ceaselessly, immeasurably, interminably, endlessly.
perpetually (adverb)
lastingly, unceasingly, always, uninterruptedly, infinitely, enduringly, everlastingly, permanently, interminably, continually, Immortally, ceaselessly, endlessly, incessantly, constantly.

adv.

all (adverb)
evermore, everlastingly, forever.
durably (adverb)
Durably, Endurably, lengthily, perennially.
endlessly (adverb)
perpetually, regularly, continually, evermore, forever, always.
ever (adverb)
endlessly.
infinitely (adverb)
incalculably, Timelessly, limitlessly, perpetually, unboundedly, boundlessly, inexhaustibly, immeasurably, innumerably, illimitably.
perpetually (adverb)
lastingly, unceasingly, always, uninterruptedly, infinitely, enduringly, everlastingly, permanently, interminably, continually, Immortally, ceaselessly, endlessly, incessantly, constantly.

n.

frequently, often, repeatedly, all the time, common, perpetual, continual, a lot, frequent. never-ending, long, on and on, lasting, for some time, constant, extended, enduring, prolonged, long-term. eternally (noun)
evermore, everlastingly, forever.
forever (noun)
regularly.

Other synonyms:

Other relevant words:
frequently, lasting, perpetual, continual, enduring, long, evermore, constant, forever.

Usage examples for eternally

  1. He also made man and woman; and his design was to make them eternally happy and blessed. – A Sermon Preached at the Quaker's Meeting House, in Gracechurch-Street, London, Eighth Month 12th, 1694. by William Penn
  2. They could not, he argued, be separated eternally – The Complete Project Gutenberg Works of George Meredith by George Meredith
  3. It was absurd to think that her father should eternally come between her and me. – The Blue Germ by Martin Swayne