Then went to 1913 dictionary. As I’d thought, accented first syllable, but dictionary doesn’t indicate if “t” is pronounced. My French is very bad, so will have to look that up as well… but not right now!
Jab”ot (?), n. [F.] 1. Originally, a kind of ruffle worn by men on the bosom of the shirt. 2. An arrangement of lace or tulle, looped ornamentally, and worn by women on the front of the dress.
Wonder if this photo from Poiret’s Murder on the Links qualifies? It appears actually sewn onto the bodice, rather than fluttering at the neckline… attenuated jabot? morphed jabot? misplaced jabot?!