guessingly

From guessing +‎ -ly.

guessingly (not comparable)

1. (rare) By way of conjecture; using guesswork.
   • c. 1603–1606, William Shakespeare, “The Tragedie of King Lear”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act III, scene vii]:

     I have a letter guessingly set down

• “guessingly”, in Webster’s Revised Unabridged Dictionary, Springfield, Mass.: G. & C. Merriam, 1913, →OCLC.