Meaning

adjective extraordinarily large in size or extent or amount or power or degree; ; ; ; - Walter Lippman

adjective extraordinarily good or great ; used especially as intensifiers

adjective extreme in degree or extent or amount or impact

originAdapted borrowing of Latin tremendus (“fearful, terrible”, gerundive of tremō (“to tremble”)) + -ous. Doublet of tremend.

Etymology from Wiktionary, CC BY-SA 3.0