MOST PROBABLY is a phrase used to express a high degree of certainty. The crossword solutions for this term are APPARENTLY (10 letters), DOUBTLESS (9 letters), and INALLIKELIHOOD (15 letters). APPARENTLY is an adverb meaning 'clearly visible or understood' and is often used to describe something that is obvious. DOUBTLESS is an adverb meaning 'without doubt' and is used to express certainty. INALLIKELIHOOD is an adverb meaning 'very likely' and is used to express a high probability. All three words can be used to express the idea of MOST PROBABLY.