1Having a single layer; consisting of one layer only (not layered or lined).
このコートは一重仕立てなので、真冬には少し寒い。
This coat is single-layered, so it's a bit cold in midwinter.
風呂敷は一重に包んで持ち帰った。
I wrapped it in a single layer of furoshiki and took it home.
この建物は壁が一重しかないため、防音性が低い。
Because the building has only a single-layer wall, its soundproofing is poor.
2In botany, describing a flower with a single row of petals (monopetalous or single-petaled).
このバラは一重で花びらが少ないが、野趣がある美しさがある。
This rose is single-petaled with few petals, but it has a natural rustic beauty.
3In kimono terminology, an abbreviation referring to an unlined kimono (a 'hitoe').
夏は一重の着物が涼しくて着やすい。
In summer, an unlined kimono is cool and easy to wear.
4A single-fold eyelid; an upper eyelid without a crease (commonly called a 'single eyelid').
彼女は一重の目がチャームポイントだ。
Her single-fold eyelids are a charming point.
一重の人はアイメイクで印象を変えることが多い。
People with single eyelids often change their look with eye makeup.