Old English cnocian (West Saxon cnucian), "to pound, beat; knock (on a door)," likely of imitative origin. Figurative meaning "deprecate, put down" is from 1892. Related: Knocked; knocking. Of engines from 1869. To knock back (a drink) "swallow quickly or at a gulp" is from 1931. Many phrases are in reference to the auctioneer's hammer, for example knock down (v.) "dispose of (something) at auction" (1760).
c. 1300, "in circumference, in a circle, on every side," from phrase on round; see a- (1) + round (adj.). Rare before 1600. In sense of "here and there with no fixed direction" it is attested from 1776 in American English (British English prefers about). As a preposition, "on or along a circuit," late 14c.; "on all sides, encircling, about" 1660s; of time, by 1873. To have been around "gained worldly experience" is from 1927, U.S. colloquial; to get around to it is from 1864.
Others are reading
<a href="https://www.etymonline.com/word/knockabout">Etymology of knockabout by etymonline</a>
Harper, D. (n.d.). Etymology of knockabout. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/knockabout