1
general::
1. Ruin the aspirations of, disappoint, as in Bill was hoping Sharon would go out with him, but she shot him down. 2. Reject, defeat; also, expose as false. For example, It was the best idea I could come up with, but they unanimously shot it down, or It was inevitable that they would shoot down any claim made by the opposing candidate. This colloquial expression, which alludes to bringing down an aircraft or game bird by shooting, is sometimes intensified as shoot down in flames, originally (in World War I) referring to bringing down enemy aircraft but by the late 1950s extended to decisively defeating anyone or anything.
American Heritage Idioms
2
general::
Phrase(s): shoot something down
Fig. to foil a plan through criticism; to counter an idea with criticism. (Based on shoot someone, something, or an animal down.) • He raised a good point, but the others shot him down almost immediately. • Liz shot down Jeff ’s best idea., Phrase(s): shoot someone, something, or an animal down
to bring down someone, something, or an animal by gunfire. • Fred shot Mike down in the street. • They shot down the plane.
McGrawhill's American Idioms And Phrasal Verbs