resettle v.

word-forming element meaning "back, back from, back to the original place;" also "again, anew, once more," also conveying the notion of "undoing" or "backward," etc. (see sense evolution below), c. 1200, from Old French re- and directly from Latin re- an inseparable prefix meaning "again; back; anew, against."

Watkins (2000) describes this as a Latin combining form conceivably from Indo-European *wret-, metathetical variant of *wert- "to turn." De Vaan says the "only acceptable etymology" for it is a 2004 explanation which reconstructs a root in PIE *ure "back."

In earliest Latin the prefix became red- before vowels and h-, a form preserved in redact, redeem, redolent, redundant, redintegrate, and, in disguise, render (v.). In some English words from French and Italian re- appears as ra- and the  following consonant is often doubled (see rally (v.1)).

The many meanings in the notion of "back" give re- its broad sense-range: "a turning back; opposition; restoration to a former state;" "transition to an opposite state." From the extended senses in "again," re- becomes "repetition of an action," and in this sense it is extremely common as a formative element in English, applicable to any verb. OED writes that it is "impossible to attempt a complete record of all the forms resulting from its use," and adds that "The number of these is practically infinite ...."   

Often merely intensive, and in many of the older borrowings from French and Latin the precise sense of re- is forgotten, lost in secondary senses, or weakened beyond recognition, so that it has no apparent semantic content (receive, recommend, recover, reduce, recreate, refer, religion, remain, request, require). There seem to have been more such words in Middle English than after, e.g. recomfort (v.) "to comfort, console; encourage;" recourse (n.) "a process, way, course." Recover in Middle English also could mean "obtain, win" (happiness, a kingdom, etc.) with no notion of getting something back, also "gain the upper hand, overcome; arrive at;" also consider the legal sense of recovery as "obtain (property) by judgment or legal proceedings." 

And, due to sound changes and accent shifts, re- sometimes entirely loses its identity as a prefix (rebel, relic, remnant, restive, rest (n.2) "remainder," rally (v.1) "bring together"). In a few words it is reduced to r-, as in ransom (a doublet of redemption), rampart, etc.

It was used from Middle English in forming words from Germanic as well as Latin elements (rebuild, refill, reset, rewrite), and was used so even in Old French (regret, regard, reward, etc.).

Prefixed to a word beginning with e, re- is separated by a hyphen, as re-establish, re-estate, re-edify, etc. ; or else the second e has a dieresis over it: as, reëstablish, reëmbark, etc. The hyphen is also sometimes used to bring out emphatically the sense of repetition or iteration : as, sung and re-sung. The dieresis is not used over other vowels than e when re is prefixed : thus, reinforce, reunite, reabolish. [Century Dictionary, 1895]

Middle English setlen, "become set or fixed, stable or permanent; seat, place in a seat; sink down, come down," from Old English setlan "place in a fixed or permanent position; cause to sit, place in a seat," from setl "a seat" (see settle (n.)). Compare German siedeln "to settle; to colonize."

From c. 1300 in reference to birds, etc., "to alight." From early 14c. of ground, etc., "to sink down, descend; cave in." By early 15c. (Chauliac) in reference to a liquid, "change from a disturbed or muddy condition to one of cleanness." By 1570s, of persons, "change from a disturbed or troubled state to one of security." 

It is attested by 1520s as "become calm" (but c. 1600 it also could mean, colloquially, "knock down dead or stunned"). The meaning "decide, set or fix as by purpose or intention" is by 1620s. The meaning "secure title to (property, etc.) by means of a deed, etc." is from 1660s. It is attested by 1733 as "put beyond dispute or establish by authority or argument;" hence "resolve, determine, come to a decision (1782).

The sense of "establish a permanent residence" is recorded by 1620s; that of "plant with inhabitants, colonize" is by 1702.

The old meaning "reconcile" (a quarrel, differences, etc.) perhaps is influenced by or merged with Middle English sahtlen "to reconcile," which is from Old English saht "reconciliation," from Old Norse satt "reconciliation."

To settle down (intrans.) as what married couples do in establishing a domestic state is by 1835 (settle alone in this sense is by 1718). The transitive sense is by 1520s. To settle for "content oneself with" is from 1943; Middle English also used settle (v.) in an intransitive sense of "come down in the world, become lower in estate" (mid-14c.).

"act of resettling; a fresh settlement," in any sense, 1630s, from resettle + -ment. In a South African racial context from 1954.