fall down

present singular third person falls down · participle present falling down · past fell down · participle past fallen down

1. intransitiveTo fall to the ground. To collapse.

   The beams supporting the roof had rotted, causing the entire house to fall down.

   3 more examples

   Ring a-ring o' roses, / A pocketful of posies. / A-tishoo! A-tishoo! / We all fall down. — traditional nursery rhyme (British version)

   Out of spite, the human beings pretended not to believe that it was Snowball who had destroyed the windmill: they said that it had fallen down because the walls were too thin.

   1943 November – 1944 February (date written; published 1945 August 17), George Orwell [pseudonym; Eric Arthur Blair], Animal Farm […], London: Secker & Warburg, published May 1962, →OCLC

   He describes the operation thus: "The heavy ram employed to impart the finishing strokes, hoisted up with double purchase and snail's pace to the summit of the Piling Engine, and then falling down like a thunderbolt on the head of the devoted timber, driving it perhaps a single half inch in to the stratum below, is well calculated to put to the test the virtue of patience, while it illustrates the old adage of—slow and sure."

   1952 July, W. R. Watson, “Sankey Viaduct and Embankment”, in Railway Magazine, page 487

   Synonyms: drop, fall, collapse, fall

2. nauticalTo sail or drift toward the mouth of a river or other outlet.
3. figurativelyintransitiveTo fail; to make a mistake.

   That is where your reasoning falls down.