1
general::
1. Kill, especially by gunshot or explosion. For example, The unit reported that the whole village was blown away. This usage became particularly widespread in the 1960s, during the Vietnam War. [Slang; early 1900s] 2. Overcome easily; defeat decisively. For example, Ann said the test would be easy; she would just blow it away, or Jim was sure his crew could blow away their opponents. [Slang; 1960s] Also see BLOW OFF, def. 5. 3. Impress greatly, overwhelm with surprise, delight, or shock, as in That music really blew me away. [Slang; c. 1970] Also see BLOW ONE'S MIND.
American Heritage Idioms
2
general::
Phrase(s): blow someone away
1. Sl. [for something shocking or exciting] to overwhelm a person; to excite a person very much. • The amount of the check blew me away. • The loud noise from the concert blew me away. 2. Sl. to murder someone, usually by gunfire. • Mr. Big ordered Lefty to blow Max away. • Max tried to blow Lefty away., Phrase(s): blow away
[for something light] to be carried away by the wind. • The leaves blew away on the autumn winds. • My papers blew away!, Phrase(s): blow someone or something away
[for the wind] to carry someone or something away. • The wind almost blew her away. • It nearly blew away all the houses.
McGrawhill's American Idioms And Phrasal Verbs