a fortiori
adverb
a for·ti·o·ri ˌā-ˌfȯr-shē-ˈȯr-ˌī 
ˌä-ˌfȯr-shē-ˈȯr-ē
ˌä-ˌfȯr-shē-ˈȯr-ē -ˌfȯr-tē-
: 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
Did you know?
A fortiori in Latin literally means "from the stronger (argument)". The term is used when drawing a conclusion that's even more obvious or convincing than the one just drawn. Thus, if teaching English grammar to native speakers is difficult, then, a fortiori, teaching English grammar to nonnative speakers will be even more challenging.
Example Sentences
Recent Examples on the Web That international reality applies a fortiori to the U.S: There is no good reason that the U.S. should engage in mindless economic sacrifice. 
Benjamin Zycher, National Review, 13 Aug. 2021 That is the case even when charges against the person are being contemplated; a fortiori, there is no excuse for gratuitously embarrassing someone who is suspected of no wrongdoing. James Freeman, WSJ, 19 Apr. 2018
Benjamin Zycher, National Review, 13 Aug. 2021 That is the case even when charges against the person are being contemplated; a fortiori, there is no excuse for gratuitously embarrassing someone who is suspected of no wrongdoing. James Freeman, WSJ, 19 Apr. 2018 Word History
Etymology
borrowed from Medieval Latin ā fortiōrī, short for ā fortiōrī ratiōne, literally, "from the stronger reason"
First Known Use
1561, in the meaning defined above
Legal Definition
a fortiori
adverb
a for·ti·o·ri ˌā-ˌfȯr-shē-ˈōr-ˌī, ˌä-ˌfȯr-shē-ˈōr-ē, -ˌfȯr-tē-
: all the more certainly : with greater reason : with still more convincing force —used in drawing a conclusion that is thought to be even more certain than another
the evident purpose of the latter statute — to provide a distinct and more severe sentencing scheme for violent habitual offenders — plainly suggests that the Legislature intended it to apply, a fortiori, to murderers as well as to criminals who commit other violent, but less serious, felonies People v. Jenkins, 893 P.2d 1224 (1995)
People v. Jenkins, 893 P.2d 1224 (1995)