GG5 and 中辞典 simply xref this to their 甚兵衛 entries. Their glosses are:
GG5: light cotton summer clothing consisting of knee-length shorts and short-sleeved jacket, often worn at festivals.
中辞典: a men's summer outfit of knee-length pants and short-sleeved jacket.
Our 甚兵衛 gloss is "informal summer clothes for men (short jacket and trousers)"

I think I'll align both with the GG5 version. I don't think the romanized version is current enough in English to lead the gloss.

@@ -13 +13 @@
-<gloss>jinbei (traditional summertime casual wear, usu. worn around the house)</gloss>
+<gloss>light cotton summer clothing consisting of knee-length shorts and short-sleeved jacket</gloss>

Yukata vs Kimono: What’s the Difference?
https://shop.japanobjects.com/blogs/editorial/yukata-kimono
An alternative to the yukata for men to wear in the summer is jinbei. Jinbei are two-piece garments consisting of a kimono-like top and loose-fitting, mid-calf length trousers. 

https://en.wikipedia.org/wiki/Jinbei
 is a traditional set of Japanese clothing worn by men, women and children during summer as loungewear.[1] 
 jinbei were originally menswear only, though in recent years, women's jinbei have become popular.

Ladies' jinbei tend to be more brightly coloured, and often feature prints of popular culture characters and motifs.

https://kurashi.biglobe.ne.jp/item_yukata/
#1 match, lady's jinbei (with pics)
レディース甚平

You can shop for Jinbei on amazon U.S.:
https://www.amazon.com/Jinbei/s?k=Jinbei

xref will need to be aligned.

Evidently no longer limited to men. Eminently googlable:
"レディース甚平" 909
レディースじんべい	52

you can shop for "jinbei" on american amazon.  recommend handling like "yukata" entry.

"short jacket and trousers" doesn't clarify much. And the jacket isn't even short, it's long.  The sleeves are short. And traditionally there were no trousers.  Quite traditional looking Japanese clothing.

the dated daijs gloss seems to say "sleeveless knee-length haori, summer, indoors, men and boys, traditionally with a sash/belt"
https://kotobank.jp/word/甚兵衛-82534#E3.83.87.E3.82.B8.E3.82.BF.E3.83.AB.E5.A4.A7.E8.BE.9E.E6.B3.89

I've offered the smallest gloss that isn't wrong, and gets the consistent-over-time points across.

Alternatively, if the constituents must be defined, japanobjects.com did a pretty concise job (for a modern jinbei):
    two-piece garments consisting of a kimono-like top and loose-fitting, mid-calf length trousers

But this leaves off the nuance of summer, informal, in-the-house, etc.

How much information are we willing to include in a gloss/expl?

Didn't used to include pants(if we claim pants, may mislead readers of not-that-old texts). Was more of a long robe
Used to be men only (maybe 30 years ago?)
Then men & kids
Now popular with men, women, and children
Traditionally for wear around the house
But you can wear it out on some occasions in place of yukata, maybe?
Traditionally simple single-colored fabrics
Now sometimes ornately decorated (for women in particular)

@@ -13 +13 @@
-<gloss>informal summer clothes for men (short jacket and trousers)</gloss>
+<gloss>jinbei (traditional summertime casual wear, usu. worn around the house)</gloss>

Entry created