凹 おう Meanings Prefix concave; hollow; sunken See also: 凹レンズ (おうレンズ). Kanji 凹 concave. Read as オウ. Words containing 凹 凹凸 (おうとつ) unevenness 凸凹 (でこぼこ) unevenness 凹版印刷 (おうはんいんさつ) intaglio printing And 16 more. Jinuma: Japanese Dictionary · Word lists