tremendous (adj.)
1630s, "awful, dreadful, terrible," from Latin tremendus "fearful, to be dreaded, terrible," literally "to be trembled at," gerundive form of tremere "to tremble" (see tremble (v.)). Hyperbolic or intensive sense of "extraordinarily great or good, immense" is attested from 1812, paralleling semantic changes in terrific, terrible, dreadful, awful, etc. Related: Tremendously.