Akademik

fall down
verb
lose an upright position suddenly
-

The vase fell over and the water spilled onto the table

-

Her hair fell across her forehead

Syn: ↑fall
Derivationally related forms: ↑fall (for: ↑fall)
Hypernyms: ↑change posture
Verb Group: ↑fall
Verb Frames:
-

Somebody ——s

* * *

be shown to be inadequate or false; fail

the deal fell down partly because there were a lot of unanswered questions

* * *

ˌfall ˈdown derived
to be shown to be not true or not good enough

And that's where the theory falls down.

see also fall v. (2)
Main entry:fallderived

Useful english dictionary. 2012.