Entry 2 senses · 2 variants Webster, 1913 Conjecturally · Con·jec·tur·al·ly · IPA n. adv. 01 n. That which depends upon guess; guesswork. 1. That which depends upon guess; guesswork.[R.] 02 adv. In a conjectural manner; by way of conjecture. 1. In a conjectural manner; by way of conjecture.