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.
c. 1300, "dreadful, terrible," from Old French horrible, orrible (12c.) "horrible, repugnant, terrifying," from Latin horribilis "terrible, fearful, dreadful" (source also of Spanish horrible, Portuguese horrivel, Italian orribile), from horrere "be terrified, bristle with fear, shudder" (see horror). Used as a mere intensifier from mid-15c.
early 15c., "stupefactive;" 1590s, "dreadful;" present-participle adjective from amaze. The sense of "wonderful" is recorded from 1704. Related: Amazingly; amazingness.
late 14c., "dung, excrement, feces; filth, dirt," from Old French ordure "filth, uncleanliness" (12c.), from ord, ort "filthy, dirty, foul," from Latin horridus "dreadful" (see horrid). Related: Ordurous.
1650s, from Latin horrendus "dreadful, fearful, terrible," literally "to be shuddered at," gerundive of horrere "to bristle with fear, shudder" (see horror). Earlier form in English was horrend (mid-15c.).
Old English unhalig, "impious, profane, wicked," from un- (1) "not" + halig (see holy). Similar formation in Middle Dutch onheilich, Old Norse uheilagr, Danish unhellig, Swedish ohelig. In reference to actions, it is attested from late 14c. Colloquial sense of "awful, dreadful" is recorded from 1842.
"causing or attended by great fear, dreadful, awful," 1560s, from Latin dirus "fearful, awful, boding ill," a religious term, which is of unknown origin. Apparently a dialect word in Latin; perhaps from Oscan and Umbrian and perhaps cognate with Greek deinos "terrible," Sanskrit dvis- 'hate, enmity, enemy," from PIE root *dwei-, forming words for "fear; hatred."