"to put off till another day, defer to a future time," 1580s, a back formation from procrastination or else from Latin procrastinatus, past participle of procrastinare "to put off till tomorrow; defer, delay." Intransitive sense of "be dilatory" is by 1630s. Related: Procrastinated; procrastinating. The earlier verb was procrastine (1540s), from French procrastiner.
Do not put off till tomorrow what can be put off till day-after-tomorrow just as well. ["Mark Twain," "Advice to Young People," 1882]
"one who defers to doing of anything to a future time," c. 1600, agent noun in Latin form from procrastinate (v.).
Old English dwellan "to lead into error, deceive, mislead," related to dwelian "to be led into error, go wrong in belief or judgment," from Proto-Germanic *dwaljana "to delay, hesitate," *dwelana "go astray" (source also of Old Norse dvelja "to retard, delay," Danish dvæle “to linger, dwell,” Swedish dväljas “to dwell, reside;” Middle Dutch dwellen "to stun, perplex;" Old High German twellen "to hinder, delay") from PIE *dhwel-, extended form of root *dheu- (1) "dust, cloud, vapor, smoke" (also forming words with the related notions of "defective perception or wits").
The apparent sense evolution in Middle English was through "to procrastinate, delay, be tardy in coming" (late 12c.), to "linger, remain, stay, sojourn," to "make a home, abide as a permanent resident" (mid-14c.). From late 14c. as "remain (in a certain condition or status)," as in phrase dwell upon "keep the attention fixed on." Related: Dwelled; dwelt (for which see went); dwells.
It had a noun form in Old English, gedweola "error, heresy, madness." Also compare Middle English dwale "deception, trickery," from Old English dwala or from a Scandinavian cognate (such as Danish dvale "trance, stupor, stupefaction"); dwale survived into late Middle English as "a sleeping potion, narcotic drink, deadly nightshade."