"1 more than one, the number which is one more than one; a symbol representing this number;" Old English twa "two," fem. and neuter form of twegen "two" (see twain), from Proto-Germanic *twa (source also of Old Saxon and Old Frisian twene, twa, Old Norse tveir, tvau, Dutch twee, Old High German zwene, zwo, German zwei, Gothic twai), from PIE *duwo, variant of root *dwo- "two."
Two-fisted is from 1774. Two cheers for _____, expressing qualified enthusiasm first recorded 1951 in E.M. Forster's title "Two Cheers for Democracy." Two-dimensional is recorded from 1883; figurative sense of "lacking substance or depth" is attested from 1934.
dance style, 1893, from two + step (n.); so called for the time signature of the music (as distinguished from the three-step waltz). But as the positions taken by the dancers involved direct contact, it was highly scandalous in its day and enormously popular.
A certain Division of an Auxiliary gave a dance not long since. I went and looked on. What did they dance? Two-step, two-step and two-step. How did they dance? When we used to waltz, we clasped arms easily, took a nice, respectable position, and danced in a poetry of motion. Now, girls, how do you two-step? In nine cases out of ten the dear girl reposes her head on the young man's shoulder, or else their faces press each other. He presses her to his breast as closely as possible, and actually carries her around. Disgraceful? I should say so. Do you wonder at the ministers preaching on dancing as a sin, when it looks like this to a woman like myself who believes in dancing and has danced all her life? Mothers, as you love your girls, forbid them to dance after this manner. [letter in the ladies' section of Locomotive Engineers' Monthly Journal, March 1898]
To the Two Step may be accredited, serious injury to the Waltz, awkward and immodest positions assumed in round dancing, also as being a prominent factor in overcrowding the profession and causing a general depression in the business of the legitimate Master of Dancing. [The Director, March 1898]