*bhle-

Proto-Indo-European root meaning "to blow, swell," "with derivatives referring to various round objects and to the notion of tumescent masculinity" [Watkins].

It forms all or part of: bale (n.) "large bundle or package of merchandise prepared for transportation;" baleen; ball (n.1) "round object, compact spherical body;" balloon; ballot; bawd; bold; bole; boll; bollocks; bollix; boulder; boulevard; bowl (n.) "round pot or cup;" bulk; bull (n.1) "bovine male animal;" bullock; bulwark; follicle; folly; fool; foosball; full (v.) "to tread or beat cloth to cleanse or thicken it;" ithyphallic; pall-mall; phallus.

It is the hypothetical source of/evidence for its existence is provided by: Greek phyllon "leaf," phallos "swollen penis;" Latin flos "flower," florere "to blossom, flourish," folium "leaf;" Old Prussian balsinis "cushion;" Old Norse belgr "bag, bellows;" Old English bolla "pot, cup, bowl;" Old Irish bolgaim "I swell," blath "blossom, flower," bolach "pimple," bolg "bag;" Breton bolc'h "flax pod;" Serbian buljiti "to stare, be bug-eyed;" Serbo-Croatian blazina "pillow."

An extended form of the root, *bhelgh- "to swell," forms all or part of: bellows; belly; bilge; billow; bolster; budget; bulge; Excalibur; Firbolgs.

An extended form of the root, *bhleu- "to swell, well up, overflow," forms all or part of: affluent; bloat; confluence; effluent; effluvium; efflux; fluctuate; fluent; fluid; flume; fluor; fluorescence; fluoride; fluoro-; flush (v.1) "spurt, rush out suddenly, flow with force;" fluvial; flux; influence; influenza; influx; mellifluous; phloem; reflux; superfluous.

"miraculous communication of supernatural knowledge or power," 1660s, from Latin afflatus "a breathing upon, blast," figuratively "inspiration," noun use of past participle of afflare "to blow upon," from ad "to" (see ad-) + flare "to blow" (from PIE root *bhle- "to blow"). The literal meaning "a blowing or breathing upon" is rare in English, this sense being taken by afflation.