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; 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."
"place of residence, habitation, abode," mid-14c., verbal noun from dwell (v.). Earlier it meant "a stupor" (early 14c.); "delay, procrastination; a staying in a place" (c. 1300).
"to dwell together," specifically "to dwell together as husband and wife," 1530s, a back-formation from cohabitation (q.v.) or else from Late Latin cohabitare. A euphemism to describe a couple living together without benefit of marriage and usually implying sexual intercourse. Related: Cohabited; cohabiting.
mid-14c., "to move about, live, dwell; live or behave in a certain way" (senses now obsolete), from Old French and French converser "to talk, open communication between," also "to live, dwell, inhabit, reside" (12c.), and directly from Latin conversari "to live, dwell, live with, keep company with," passive voice of conversare, literally "to turn round with," from assimilated form of com "with, together" (see con-) + versare, frequentative of vertere "to turn" (from PIE root *wer- (2) "to turn, bend").
Sense of "to communicate (with)" in English is from 1590s; that of "talk informally with another" is from 1610s. Related: Conversed; conversing.