Dormant
late Middle English (in the senses ‘fixed in position’ and ‘latent’): from Old French, ‘sleeping’, present participle of dormir, from Latin dormire ‘to sleep’.
wiktionary
From Middle English, from Old French, from Latin dormiēns, present participle of dormiō(“I sleep”).
etymonline
dormant (adj.)
late 14c., "fixed in place," from Old French dormant (12c.), present participle of dormir "to sleep," from Latin dormire "to sleep," from PIE root *drem- "to sleep" (source also of Old Church Slavonic dremati "to sleep, doze," Greek edrathon "I slept," Sanskrit drati "sleeps").
Meaning "in a resting situation, lying down with the head on the forepaws" (in heraldry, of beasts) is from c. 1500. Meaning "sleeping, asleep" is from 1620s. General sense of "in a state of rest or inactivity" is from c. 1600. Of volcanoes from 1760.
The Neapolitans are never so much afraid of this fiery Mountain as when its Flames lie, as 'twere, dormant ; for then it is that they live in constant Fear of a fresh huge Eruption, or, much worse, an Earthquake. [from the entry for "Vesuvius" in Brice's "Grand Gazetter Or Topographic Dictionary," 1760]
