GG5: 胴切りにした 《salmon》 steak; 《fish》 cut into steaks.
ルミナス equates it to 輪切り (cutting in round slices; round slice)
Koj, Daijr/s: 胴を横に切ること。 etc.

Possibly 胴斬り and sense 2 should be in a different entry.

@@ -9 +8,0 @@
-<ke_inf>&sK;</ke_inf>
@@ -25 +24 @@
-<gloss>horizontal cut across the stem of a plant (esp. a succulent for propagation)</gloss>
+<gloss>horizontal cut (esp. fish, plant, etc.)</gloss>

胴切り	3074	59.6% (cacti)
どう切り	958	18.6%
を胴切り	148　   ([vt] for cacti)
胴斬り	789	15.3% (swords and cacti!)
を胴斬り	29　yourei: 相手を胴斬りにして, 人を胴斬りにしている, ie. を。。。にする, not [vs]
どう斬り	143	2.8%
どうぎり	79	1.5%
どうぎり	79	1.5%

more yourei examples(can't find [vs] evidence for the sword):
胴斬りになった死人
武士たちは胴斬りになって
一刀の下もとに胴斬にされていた
相手を胴斬りにしてしまった
からだを胴斬りに切断された女
二段に胴斬りにし
一瞬の胴斬りに倒した

https://www.joyusgarden.com/propagate-succulents
I most often propagate succulents by stem cuttings.

stem cutting = 胴切り

good cactus picture for you:
サボテンを胴切りして群生株を作ろう！
https://supersabotentime.com/4379/

Same phenomenon, in English:
Propagating Cactus
https://thesucculentsource.com/blogs/succulent-cactus-news/propagating-cactus

Another picture of another cut (with a string, probably) of a different kind of succulent:
https://twitter.com/jvMkTBSycQZ8ThK/status/1645614091334213632

https://www.weblio.jp/content/胴切り
daijs: 胴の部分で横に切ること。輪切り。筒 (つつ) 切り。

Google Image search for 胴切り (propagating succulents)
Youtube search for 胴切り (propagating succulents)
https://www.youtube.com/results?search_query=胴切り
Twitter search for 胴切り (propagating succulents)
https://twitter.com/search?q=胴切り&src=typed_query


Youtube search for 胴斬り (rakugo, swordplay practice)
https://www.youtube.com/results?search_query=胴斬り
Twitter search for 胴斬り (rakugo, swordplay practice, cactuses)
https://twitter.com/search?q=胴斬り&src=typed_query&f=top

胴斬り (note the kanji) is the subject of an evidently-well-known rakugo story(which is what appears in  the youtube search).
https://ja.wikipedia.org/wiki/胴斬り

(This is a video game fighting technique translation from Japanese into English)
https://finalfantasy.fandom.com/wiki/Final_Fantasy_XIV_action_translations
胴切り lateral slash

A different 胴切り story, which seems like it may be a precursor to the comical rakugo edition
https://lightinthecloudsblog.com/tag/hojo-tokimasa/
The last thief retreated to a room where wooded barrels used to store blessed rice wine are kept, and hid in an empty one hoping to escape later unseen. Ittōsai gave chase and... In one swift motion, he rushed at the barrel and cleaved through the barrel, which not only collapsed in two, the thief inside also fell along with it, severed from his torso down.
This remarkable feat of cleaving both the wine barrel and the thief would years later serve as a secret technique taught to his highest student, which would be called “dō-giri” (胴斬り)³.


https://www.e-budo.com/forum/showthread.php?2290-Names-of-basic-cuts
5. Yoko ichi-mo(n)ji giri (side horizontal cut). The ideograph [moji] for the number "one" [ichi] is a horizontal bar; this translates to "horizontal." Also known as:
b. Yokogiri (side cut).
c. Suihei giri (placid water cut). Placid water is flat; ergo, horizontal.
d. Dogiri (torso cut).

Glossary Related to BUDŌ (武道)and KOBUDŌ (古武道)With special reference to HONTAI YŌSHIN RYŪ (本體楊心流
https://kupdf.net/download/glossary-related-to-hontai-yoshin-ryu_5af68efbe2b6f5533deed0ea_pdf
DOGIRI (胴切り): cutting into the torso (much more horizontally than KESA)

Here's an illustration of the rakugo character(note the wise mean whose torso is seated on a barrel, his lower body seated on the ground beside him): 
https://note.com/kimi3528/n/n398f3370acd7

Here's a rakugo performance:
https://www.nicovideo.jp/watch/sm7686612

The plant usage is *very* common(more common than the sword thing...), so I put it first.　This honors the n-gram distribution as well. 

I might not have ran into this if we had the "correct" kanji for 胴斬り.  As a fairly general rule: 
胴斬り = sword to the abdomen
胴切り = plant cutting (I've seen this commonly done with *string*, so even 'knife' is not implied here)

With 切り, google autocompletes 胴切り with サボテン (cactus)

Most commonly appears for propagating succulents (cacti, etc.), but I also saw it used for the care of rotting, traditional looking cacti, where the big leafy stem has to be cut down to reach a point with no rot.

In the rakugo story, the victim is cut cleanly in half, but that doesn't seem required.

I did a lot of search to see if there was some technical term for the sword swing. Suffice it to say, 胴斬り is *practiced" more than it's executed.  So it is somewhat more accurately described as a sword swing (an actual torso is not required to say "胴斬り"). I was going to leave the gloss as is, but in the end I made some tiny changes that I think resolve this.

Here's a whole exercise workout focused on dougiri (no torsos harmed):

Let's do it every day to conquer yourself | Day12 | Dougiri with Sikodachi
https://www.youtube.com/watch?v=RRdljF3M_4o

One more thing... for the sword technique, ngrams don't show usage as a suru verb at all. I've given some yourei examples above.  If you search 胴斬り with する, the sword results basically disappear in favor of cactuses(斬 is *also* used for cactuses/cacti). I don't think [2] is [vs].

For [vs,vt] of [1], succulents, you can search "株を胴切りして"

Looking at the yourei examples (which don't completely align with your average youtube video), it seems that 胴切り could also be considered "being cut by a sword across the torso". Doesn't seem worth the clutter.

@@ -5,0 +6,11 @@
+</k_ele>
+<k_ele>
+<keb>どう切り</keb>
+<ke_inf>&sK;</ke_inf>
+</k_ele>
+<k_ele>
+<keb>胴斬り</keb>
+</k_ele>
+<k_ele>
+<keb>どう斬り</keb>
+<ke_inf>&sK;</ke_inf>
@@ -13 +24,7 @@
-<gloss>cutting horizontally into the torso (with a sword)</gloss>
+<pos>&vt;</pos>
+<gloss>horizontal cut across the stem of a plant (esp. a succulent for propagation)</gloss>
+</sense>
+<sense>
+<pos>&n;</pos>
+<s_inf>esp. 胴斬り</s_inf>
+<gloss>horizontal cut across the torso (sword technique)</gloss>