Old English sarig "distressed, grieved, full of sorrow" (not found in the physical sense of "sore"), from Proto-Germanic *sairiga- "painful" (cf. Old Saxon serag, Middle Dutch seerigh "sore; sad, sorry," Dutch zeerig "sore, full of sores," Old High German serag, Swedish sårig "sore, full of sores"), from *sairaz "pain" (physical and mental); related to *saira- "suffering, sick, ill" (see sore (adj.)). Meaning "wretched, worthless, poor" first recorded mid-13c. Spelling shift from -a- to -o- by influence of sorrow. Apologetic sense (short for I'm sorry) is attested from 1834; phrase sorry about that popularized 1960s by U.S. TV show "Get Smart." Related: Sorrily; sorriness.