alone (adj., adv.) Look up alone at Dictionary.com
"unaccompanied, solitary; without companions, solitary," c. 1300 contraction of all ane, from Old English all ana "unaccompanied, all by oneself," literally "wholly oneself," from all "all, wholly" (see all) + an "one" (see one). It preserves the old pronunciation of one. Similar compounds are found in German (allein) and Dutch (alleen). Sense of "and nothing else" ("Man shall not live on bread alone") is from c. 1200. Related: Aloneness. Adverbial alonely seems to be obsolete since 17c.