Emily Dickinson Lexicon

REAS-ON-A-BLY, adv.

1. In a manner or degree agreeable to reason; in consistency with reason. We may reasonably suppose self-interest to be the governing principle of men.
2. Moderately; in a moderate degree; not fully; degree reaching to mediocrity. If we can by industry make our deaf and dumb persons reasonably perfect in the language. – Holder.