刀 is a pictogram of a knife or sword with a single edge.¹ More clearly written out it looked like , which clearly shows the blade on top. Probably for ease of writing, the shape of 刀 was distorted early on (see below) and in those forms it is not entirely clear what part is the handle and what part the blade.²
When used as a component in composite graphs, at the right 刀 often looks like 刂, on top like ⺈.
- Ochiai writes that at the time of the Shang dynasty the main weapons of the warrior where the lance and the bow. The weapon depicted in 刀 would have been a somewhat small ancillary weapon (Ochiai, 2016, p. 355). Qiú simply writes “knife”, which Schuessler gives as the early meaning (Qiú, 2000, p. 180; Schuessler, p. 206). It seems that as the sword became more important, the word 刀 was used for that as well (Kroll, p. 78).
- Ochiai gives the example of “divide” 分 to argue that in that graph the top part is used to divide and therefore the blade. However, the graph “blade” 刃 has the mark indicating the blade usually towards or on the bottom part.