1580s, "tumble down, fall headfirst," earlier "tumble or roll about" (1540s), from top (v.) "to tip" + frequentative suffix -le. Transitive sense also is from 1590s. Related: Toppled; toppling.
Entries linking to topple
top v.
"put a top on," 1580s, perhaps mid-15c., from top (n.1). Earlier "cut the top off, shave the head" (c. 1300). The meaning "be higher or greater than" also is first recorded 1580s. Meaning "strike (a ball) towards its top" is from 1881. Related: Topped; topping. To top off "to finish" is colloquial from 1836; in sense "fill up, add more to to bring to fullness" it is from 1917.