open-necked

US /ˌoʊ.pənˈnekt/
UK /ˌoʊ.pənˈnekt/
"open-necked" picture
1.

開襟の, 襟なしの

having a collar that is not fastened at the neck, or no collar at all

:
He wore an open-necked shirt to the casual dinner.
彼はカジュアルな夕食に開襟シャツを着ていた。
The dress had an elegant open-necked design.
そのドレスはエレガントな開襟デザインだった。