worshiping 170381
worshipping 521052

I'll take a middle path.
Even AmE tends to double the "p".

@@ -13 +13 @@
-<gloss>two bows, two claps, and a third bow (form of worshiping at a shrine)</gloss>
+<gloss>two bows, two claps, and a third bow (common form of worshipping at a shrine)</gloss>

To be clear, I think any of these would be an improvement:

(a standard form of worshiping at a shrine)   # (maybe my favorite, even with the article, but we don't like articles)

(the standard form of worshiping at a shrine) # (opinionated, but probably accurate.  I think this is objectively the standard form of worshiping at a Shinto Shrine in Japan

(common form of worshiping at a shrine)       # True enough

(form of worshiping at a shrine)              # Safe but inoffensive, loses some information

Don't really need a reference for this, but I can say the wikipedia page includes the note:
なお、拝礼の作法は神社や地域によって特色があり、厳格な決まりはない[4]。 (no rules, worship etiquette may vary by shrine and region)

二礼二拍手一礼
https://ja.wikipedia.org/wiki/二礼二拍手一礼

Another historical, less common pattern is, for example:
三礼三拍手一礼

I invite comments/changes to this edit.  Sorry if this seems overly trivial, I'm making this post as a not-overly-sensitive person :)

I had replaced "standard" with "common", but ended up convincing myself to remove that as well.

My question/emotional reaction when reading this definition is "*a* standard form of worship" or "*the* standard form of worship".

Oddly, I wouldn't mind either one personally, but I don't like the feeling of trying to "guess" what the dictionary is saying.  The problem is that this practice is, so far as I can tell from personal experience and google, objectively "the standard", with the proviso that there are still other ways to do this at different shrines and different regions (different numbers of claps, different numbers of bows).  If we mean "the standard", I think "the" should be added unambiguously, even though policy shies away from articles.  If we don't want to make such a committal assertion, we could say "a standard".

Or, if we don't want an article, and don't want to take a firm stance on Japanese religious practices, "common" seems easily fair enough given the prevalence of this ritual in Japanese society.

Or, we could just say "(form of worshiping at a shrine)", the only loss being that it really is super-common, and we're no longer communicating that.

I've searched pretty much every gloss with "standard" in it, and this issue really is limited to just this, and one related entry (or I would have gone the github route).

If a change is made/accepted here, the identical change should be made to the entry 二拝二拍一拝.

@@ -13 +13 @@
-<gloss>two bows, two claps, and a third bow (standard form of worshiping at a shrine)</gloss>
+<gloss>two bows, two claps, and a third bow (form of worshiping at a shrine)</gloss>

g ng
二礼二拍手一礼	4847
二礼二拍一礼	1404
二礼二拍手一拝	292
二礼二拍一拝	35
https://www.xn--t8j4c7dy42mj9kt8e4tsjg7cfa.net/nireinihakuichirei/
”参拝で行うこの作法のことを「二礼二拍手一礼」といいます。"