derring-do n.

Middle English durren, daren, from first and third person singular of Old English durran "be bold enough, have courage" (to do something), also transitive "to venture, presume," from Proto-Germanic *ders- (source also of Old Norse dearr, Old High German giturran, Gothic gadaursan), according to Watkins from PIE root *dhers- "bold" (source also of Sanskrit dadharsha "to be bold;" Old Persian darš- "to dare;" Greek thrasys "bold," tharsos "confidence, courage, audacity;" Old Church Slavonic druzate "to be bold, dare;" Lithuanian drįsti "to dare," drąsus "courageous").

An Old English irregular preterite-present verb: darr, dearst, dear were first, second and third person singular present indicative; mostly regularized 16c., though past tense dorste survived as durst, but is now dying, persisting mainly in northern English dialect.

Transitive sense of "attempt boldly to do" is from 1630s. Meaning "to challenge or defy (someone), provoke to action," especially by asserting or implying that one lacks the courage to accept the challenge, is by 1570s. Weakened sense in I dare say (late 14c.) "I suppose, I presume, I think likely," now usually implying more or less indifference. How dare you? is from c. 1200 (Hu durre ȝe).

"perform, execute, achieve, carry out, bring to pass by procedure of any kind," etc., Middle English do, first person singular of Old English don "make, act, perform, cause; to put, to place," from West Germanic *doanan (source also of Old Saxon duan, Old Frisian dwa, Dutch doen, Old High German tuon, German tun), from PIE root *dhe- "to set, put, place."

Use as an auxiliary began in Middle English. Sense of "to put, place, lay" is obsolete except in phrases such as do away with. Periphrastic form in negative sentences (They did not think) replaced the Old English negative particles (Hie ne wendon).

Meaning "visit as a tourist" is from 1817. In old slang it meant "to hoax, cheat, swindle" (1640s). Slang meaning "to do the sex act with or to" is from 1913.

Slang do in "bring disaster upon, kill" is by 1905. To have to do with "have concern or connection with" is from late 13c. To do without "dispense with" is from 1713.  Expression do or die indicating determination to succeed despite dangers or obstacles is attested from 1620s.

Compare does, did, done.