英语词源字典 - 在线词源网站

actually (adv.)[actually 词源字典]: early 15c., "in fact, in reality" (as opposed to in possibility), from actual + -ly (2). Meaning "actively, vigorously" is from mid-15c.; that of "at this time, at present" is from 1660s. As an intensive added to a statement and suggesting "as a matter of fact, really, in truth" it is attested from 1762. [actually etymology, actually origin, 英语词源]
de facto: Latin, literally "in fact, in reality," thus, "existing, but not necessarily legally ordained;" from facto, ablative of factum "deed, act" (see fact).
fact (n.): 1530s, "action, anything done," especially "evil deed," from Latin factum "an event, occurrence, deed, achievement," in Medieval Latin also "state, condition, circumstance," literally "thing done" (source also of Old French fait, Spanish hecho, Italian fatto), noun use of neuter of factus, past participle of facere "to do" (see factitious). Main modern sense of "thing known to be true" is from 1630s, from notion of "something that has actually occurred."

Compare feat, which is an earlier adoption of the same word via French. Facts "real state of things (as distinguished from a statement of belief)" is from 1630s. In fact "in reality" is from 1707. Facts of life "harsh realities" is from 1854; euphemistic sense of "human sexual functions" first recorded 1913. Alliterative pairing of facts and figures is from 1727.
Facts and Figures are the most stubborn Evidences; they neither yield to the most persuasive Eloquence, nor bend to the most imperious Authority. [Abel Boyer, "The Political State of Great Britain," 1727]
firestorm (n.): also fire-storm, 1580s, in poetry, from fire (n.) + storm (n.). From 1945 in reality, in reference to nuclear war.
landau (n.): type of four-wheeled carriage, 1743, from Landau, town in Bavaria where they first were made. The first element is the common Germanic element found in English land (n.); the identity of the second is disputed. But Klein says the vehicle name is "in reality" Spanish lando "originally a light four-wheeled carriage drawn by mules," from Arabic al-andul.
second (adj.): "next after first," c. 1300, from Old French second, secont, and directly from Latin secundus "following, next in time or order," also "secondary, subordinate, inferior," from root of sequi "follow" (see sequel). Replaced native other in this sense because of the ambiguousness of the earlier word. Second sight is from 1610s; an etymologically perverse term, because it means in reality the sight of events before, not after, they occur. Second fiddle first attested 1809:
A metaphor borrowed from a musical performer who plays the second or counter to one who plays the first or the "air." [Bartlett, "Dictionary of Americanisms," 1848]