Etymology
Advertisement
understudy (v.)
also under-study, 1852, in the theatrical sense "memorize a part so as to be capable of performing on short notice it in the absence of the one to which it is assigned," from under + study (v.). The noun is attested from 1848, translating Italian supplimento.
Related entries & more 
Advertisement
plainness (n.)

c. 1300, plainnes, "flatness, level ground, flat surface;" late 14c., "smoothness, evenness," from plain (adj.) + -ness. Meaning "clarity, lucidity" is from mid-15c.; that of "open conduct" is from 1540s; that of "absence of ornament" is from 1580s.

Related entries & more 
apnea (n.)
in pathology, "suspension of breathing," originally, and until recently most commonly, apnoea, 1719, Modern Latin, from Greek apnoia "absence of respiration," from apnoos "without breathing, without wind," from a- "not, without" (see a- (3)) + pnein "to breathe" (see pneuma).
Related entries & more 
revenant (n.)

"one who returns," especially after a long absence; "a ghost, one who returns from the dead," 1814 (in "Rosanne" by Laetitia Matilda Hawkins), from French revenant (fem. revenante), noun use of present participle of revenir "to return" (see revenue).

Related entries & more 
analgesia (n.)
"absence of pain, incapacity of feeling pain in a part, though tactile sense is preserved," 1706, medical Latin, from Greek analgesia "want of feeling, insensibility," from analgetos "without pain, insensible to pain" (also "unfeeling, ruthless"), from an- "not" (see an- (1)) + algein "to feel pain" (see -algia). An alternative form is analgia.
Related entries & more 
Advertisement
atresia (n.)
"occlusion of a natural passage in the body, absence of a natural opening or passage," 1807, from Modern Latin atresia, from Greek atretos "not perforated," from a- "not, without" (see a- (3)) + tresis "perforation," from PIE root *tere- (1) "to rub, turn," with derivatives referring to boring and drilling. Related: Atresic.
Related entries & more 
vacuity (n.)
late 14c., "hollow space," from Latin vacuitas "empty space, emptiness, absence, vacancy, freedom," from vacuus "empty," from PIE *wak-, extended form of root *eue- "to leave, abandon, give out." Originally in anatomy. Meaning "vacancy of mind or thought" is attested from 1590s.
Related entries & more 
spare-ribs (n.)
1590s, formerly also spear-ribs, from spare (adj.), here indicating probably "absence of fat;" or perhaps from Middle Low German ribbesper "spare ribs," from sper "spit," and meaning originally "a spit thrust through pieces of rib-meat" [Klein]; if so, it is related to spar (n.1).
Related entries & more 
darkness (n.)

Old English deorcnysse "absence of light," from dark (adj.) + -ness. The 10c. Anglo-Saxon treatise on astronomy uses þeostrum for "darkness." Figurative use for "sinfulness, wickedness" is from early 14c. From late 14c. as "obscurity," also "secrecy, concealment," also "blindness," physical, mental, or spiritual.

Related entries & more 
misrule (n.)

late 14c., misreule, "bad government of a state;" see mis- (1) + rule (n.). Meaning "disorderly conduct or living, absence of control or restraint" is from c. 1400, obsolete except in Lord of Misrule, one chosen to preside over Christmas games in a great house (late 15c.). Related: Misruly.

Related entries & more 

Page 4