sob (v.) Look up sob at Dictionary.com
c.1200, probably of imitative origin, related to Old English seofian "to lament," Old High German sufan "to draw breath," West Frisian sobje "to suck."

Related: Sobbed; sobbing. The noun is attested from late 14c. Sob story is from 1913. Sob sister "female journalist who writes sentimental stories or advice columns" is from 1912.