Etymology
Advertisement
interrogation (n.)
late 14c., "a question;" c. 1500, "a questioning; a set of questions," from Old French interrogacion "a questioning" (13c.) or directly from Latin interrogationem (nominative interrogatio) "a question; questioning; judicial inquiry," noun of action from past participle stem of interrogare "to ask, question, inquire; interrogate judicially, cross-examine," from inter "between" (see inter-) + rogare "to ask, to question," apparently a figurative use of a PIE verb meaning literally "to stretch out (the hand)," from root *reg- "move in a straight line."
Related entries & more 
Advertisement
interrogator (n.)
1751, from French interrogateur (16c.) or directly from Late Latin interrogator, agent noun from Latin interrogare "to ask, question" (see interrogation).
Related entries & more 
interrogate (v.)
late 15c., a back-formation from interrogation or else from Latin interrogatus, past participle of interrogare "to ask, question, inquire; interrogate judicially, cross-examine," from inter "between" (see inter-) + rogare "to ask, to question," apparently a figurative use of a PIE verb meaning literally "to stretch out (the hand)," from root *reg- "move in a straight line." The Old French word was interroger (14c.) which yielded English interroge (late 15c.), now obsolete. Related: Interrogated; interrogating.
Related entries & more 
third degree (n.)
"intense interrogation by police," 1900, probably a reference to Third Degree of master mason in Freemasonry (1772), the conferring of which included an interrogation ceremony. Third degree as a measure of severity of burns (most severe) is attested from 1866, from French (1832); in American English, as a definition of the seriousness of a particular type of crime (the least serious type) it is recorded from 1865.
Related entries & more 
semicolon (n.)
punctuation-mark, 1640s, a hybrid coined from Latin-derived semi- + Greek-based colon (n.1). The mark itself was (and is) in Greek the point of interrogation.
Related entries & more 
Advertisement
purge (n.)

1560s, "that which purges," from purge (v.). Meaning "a purgative, an act of purging" is from 1590s. Political or social sense of "removal (from a governing body, party, army, etc.) of persons deemed undesirable" is by 1730 (in reference to Pride's Purge); modern use in reference to the Soviet Union is by 1933. The earliest sense of the word in English was "examination or interrogation in a legal court" (mid-15c.), a sense now obsolete even if the feeling persists.

Related entries & more 
question (n.)

early 13c., questioun, "philosophical or theological problem" (especially when phrased as an interrogative statement), early 14c. as "utterance meant to elicit an answer or discussion," also as "a difficulty, a doubt," from Anglo-French questiun, Old French question "question, difficulty, problem; legal inquest, interrogation, torture," and directly from Latin quaestionem (nominative quaestio) "a seeking, a questioning, inquiry, examining, judicial investigation," noun of action from past-participle stem of quaerere "ask, seek" (see query (v.)).

Also in Middle English "verbal contention, debate; legal proceedings, litigation, accusation." Phrase a question of meaning "a dispute about" is from early 15c.

No question "undoubtedly" is from mid-15c; no questions asked "accountability not required" is from 1879 (especially in newspaper advertisements seeking the return of something lost or stolen). To be out of the question (c. 1700) is to be not pertinent to the subject, hence "not to be considered." To be in question "under discussion or consideration" is from 1610s.

Question mark is from 1849, sometimes also question stop (1862), earlier interrogation point (1590s). The figurative sense of "something about which there is uncertainty or doubt" is from 1869.  

Related entries & more