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Webster 1828 Edition

adv.

With quivering or trepidation.

tremulously ‎(comparative more tremulously, superlative most tremulously)

In a trembling, quivering, or shaking manner.
In a timid, hesitant, or unconfident manner.
- 1912, Zane Grey, Riders of the Purple Sage, Chapter 20
  "Are you—all—all right?" she asked, tremulously.