early 15c., desiccacioun, "a drying out," from Late Latin desiccationem (nominative desiccatio), noun of action from past-participle stem of Latin desiccare "to make very dry," from de- "thoroughly" (see de-) + siccare "to dry" (see siccative). From 1540s as "act of making dry; state of being dry."

1570s (past-participle adjective desicatt is attested from early 15c.), transitive, "to dry, deprive of moisture," from Latin desiccatus, past participle of desiccare "to make very dry," from de- "thoroughly" (see de-) + siccare "to dry" (see siccative). Intransitive sense of "become dry" is from 1670s. Related: Desiccated; desiccating.

1806, in botany, "dry and shriveled," from Modern Latin scariosus "dry and shriveled," which is of obscure origin.

of wine, "dry," 1863, an English use of French sec (10c.), from Latin siccus "dry" (also source of Italian secco); see siccative.

"act or operation of drying; evaporation of moisture," 1590s, from Late Latin exsiccationem "a drying up," noun of action from past-participle stem of Latin exsiccare "dry up, make quite dry," from ex "out" (see ex-) + siccare "make dry" (see siccative).

also *es-, Proto-Indo-European root meaning "to burn, glow." 

It forms all or part of: ardent; ardor; area; arid; aridity; aril; arson; ash (n.1) "powdery remains of fire;" azalea; potash; potassium.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit asah "ashes, dust;" Hittite hat- "to dry up;" Greek azein "to dry up, parch," azaleos "dry;" Latin aridus "parched, dry," ārēre "to be dry," āra "altar, hearth;" Armenian azazem "I dry up;" Old English æsce "ash," Old High German asca, Gothic azgo "ashes." 

"of the same earth or world," 1640s, from Latin conterraneus, from assimilated form of com "with, together" (see con-) + terra "earth, land" (literally "dry land," from PIE root *ters- "to dry").