Where does “terrifically” come from?

Terrifically derives from English terrific plus the Middle English adverbial suffix -ally, ultimately from Latin terrificus meaning "causing terror."

terrifically (English): In a terrific or extreme way

Definitions

  1. In a terrific or extreme way

Ancestry of “terrifically”, step by step

StepLanguageWordMeaning
1English-allyused with adjectives ending in -ic
2EnglishahistoricSynonym of ahistorical
3EnglishhistoricVery important; noteworthy: having importance or...
4Latinhistoricushistorical
5Latinhistoriahistory; account; story
6Ancient Greekἱστορίαinquiry, examination, systematic observation,...
7Ancient Greekἱστορέωto inquire, ask; to examine, observe; to record,...
8Ancient Greekἵστωρone who knows law and right, judge; witness; a...
9Proto-Hellenicwístōr—
10Proto-Indo-Europeanwéydtōrone who has seen, one who knows
11Indo-European*weyd-—
Every word from Indo-European *weyd- →Every word from English -ally →Every word from Proto-Indo-European wéydtōr →