1.To feel weird when you don’t realize that you did something bad; synonym(s): bad, weird, unrealizable, nervous. Steve was blaph because he broke a window made out of glass.
Circa 2012. Modern English < idle, meaningless talk," 1918, probably echoic; the adj. meaning "bland, dull" is from 1919, perhaps infl. by Fr. blasé "bored, indifferent." The blahs "depression" is first attested 1969. c.1300, fantum "illusion, unreality," from O.Fr. fantesme (12c.), from V.L. *fantauma, from L. phantasma (see phantasm). The ph- restored in Eng. c.1590. Meaning "specter, spirit, ghost" is attested from 1382; that of "something having the form, but not the substance, of a real thing" is from 1707. Source: dictionary.com