balk Look up balk at Dictionary.com
O.E. balca "ridge, bank," from or influenced by O.N. balkr "ridge of land," especially between two plowed furrows, both from P.Gmc. *balkan-, *belkan- (cf. O.S. balko, Dan. bjelke, O.Fris. balka, O.H.G. balcho, Ger. Balken "beam, rafter"), from PIE *bhelg- "beam, plank" (cf. L. fulcire "to prop up, support," fulcrum "bedpost;" Lith. balziena "cross-bar;" and possibly Gk. phalanx "trunk, log, line of battle"). Modern senses are figurative, either representing the balk as a hindrance or obstruction (e.g., of horses, "to stop short before an obstacle," recorded from late 15c.), or from the verb sense of "to miss or omit intentionally" (attested by late 15c.) as a lazy or incompetent plowman would in making balks. Baseball sense is first attested 1845. Related: Balky (1847).