[a for.ti.o.ri] adv [NL, lit., from the stronger (argument)] (1588): with greater reason or more convincing force--used in drawing a conclusion that is inferred to be even more certain than another "the man of prejudice is, a fortiori, a man of limited mental vision"
A FORTIORI
Meaning of A FORTIORI in English
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012