double (v.)youdaoicibaDictYouDict
late 13c., "make double," from Old French dobler, from Latin duplare, from duplus (see double (adj.)). Meaning "to work as, in addition to one's regular job" is c. 1920, circus slang, from performers who also played in the band. Related: Doubled; doubling. To double up bodily is from 1814.
A blow on the stomach "doubles up" the boxer, and occasions that gasping and crowing which sufficiently indicate the cause of the injury .... [Donald Walker, "Defensive Exercises," 1840]
gasp (v.)youdaoicibaDictYouDict
late 14c., gaspen, "open the mouth wide; exhale," of uncertain origin, perhaps from Old Norse geispa "to yawn," or its Danish cognate gispe "gasp," which probably are related to Old Norse gapa "open the mouth wide" (see gap (n.)). Related: Gasped; gasping.
pant (n.)youdaoicibaDictYouDict
"a gasping breath," c. 1500, from pant (v.).