The Collaborative International Dictionary of English v.0.48:

Youngly \Young"ly\, a. [AS. geonglic.]
   Like a young person or thing; young; youthful. [Obs.] --Shak.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Youngly \Young"ly\, adv.
   1. In a young manner; in the period of youth; early in life.
      [Obs.] --Shak.
      [1913 Webster]

   2. Ignorantly; weakly. [R.]
      [1913 Webster]