| 背光 | bèi guāng | be in a poor light; do something with one's back to the light; stand in one's own light |
| 光临 | guāng lín | (honorific) Welcome!; You honor us with your presence.; It is an honor to have you. |
| 光州 | Guāng zhōu | Guangzhou, old name for Huangchuan 潢川 in Xinyang 信阳, Henan; Gwangju Metropolitan City, capital of South Jeolla Province 全罗南道, South Korea |
| 反光镜 | fǎn guāng jìng | reflector; reflecting mirror |
| 沾光 | zhān guāng | to bask in the light; fig. to benefit from association with sb or sth; reflected glory |
| 一寸光阴一寸金 | yī cùn guāng yīn yī cùn jīn | An interval of time is worth an ounce of gold (common saying); free time is to be treasured |
一寸光阴一寸金，
寸金难买寸光阴 | yī cùn guāng yīn yī cùn jīn ,
cùn jīn nán mǎi cùn guāng yīn | An interval of time is worth an ounce of gold, money can't buy you time (common saying); Time is precious and must be treasured. |
| 一线微光 | yī xiàn wēi guāng | gleam |
| 不光彩 | bù guāng cǎi | disgraceful; dishonorable |
| 中国光大银行 | Zhōng guó guāng dà yín háng | China Everbright Bank |
| 仰光大金塔 | Yǎng guāng Dà Jīn tǎ | Great Pagoda of Yangon (Rangoon) |
| 偏光 | piān guāng | polarized light |
| 偏极滤光镜 | piān jí lǜ guāng jìng | polarizing filter |
| 充满阳光 | chōng mǎn yáng guāng | sun-drenched |
| 光二极管 | guāng èr jí guǎn | photodiode; light-emitting diode (LED) |
| 光亮度 | guāng liàng dù | brightness; luminosity |
| 光伏 | guāng fú | photovoltaic (e.g. cell) |
| 光伏器件 | guāng fú qì jiàn | photovoltaic device (e.g. solar cell) |
| 光信号 | guāng xìn hào | optical signal |
| 光光 | guāng guāng | bright; shiny; smooth; naked; bald; penniless |
| 光刻 | guāng kè | photolithography |
| 光刻胶 | guāng kè jiāo | photoresist (laser etching used in microelectronics) |
| 光前裕后 | guāng qián yù hòu | to bring honor to one's ancestors and benefit future generations (idiom) |
| 光功率 | guāng gōng lǜ | optical power |
| 光动嘴 | guāng dòng zuǐ | empty talk; mere rhetoric; palaver |
| 光化作用 | guāng huà zuò yòng | photochemical effect; photosynthesis; photolysis |
| 光化学 | guāng huà xué | photochemistry |
| 光合 | guāng hé | photosynthesis |
| 光学仪器 | guāng xué yí qì | optical instrument |
| 光学字符识别 | guāng xué zì fú shí bié | optical character recognition, OCR |
| 光学显微镜 | guāng xué xiǎn wēi jìng | optical microscope |
| 光宗耀祖 | guāng zōng yào zǔ | to bring honor to one's ancestors |
| 光射线 | guāng shè xiàn | light ray |
| 光导纤维 | guāng dǎo xiān wéi | optical fiber |
| 光山县 | Guāng shān xiàn | Guangshan county in Xinyang 信阳, Henan |
| 光州市 | Guāng zhōu shì | Guangzhou, old name for Huangchuan 潢川 in Xinyang 信阳, Henan; Gwangju Metropolitan City, capital of South Jeolla Province 全罗南道, South Korea |
| 光州广域市 | Guāng zhōu guǎng yù shì | Gwangju Metropolitan City, capital of South Jeolla Province 全罗南道, South Korea |
| 光年 | guāng nián | light-year |
| 光彩夺目 | guāng cǎi duó mù | dazzling; brilliant |
| 光影 | guāng yǐng | light and shadow; sunlight and shade |
| 光影效 | guāng yǐng xiào | lighting effect |
| 光复乡 | Guāng fù xiāng | Guangfu or Kuangfu township in Hualien county 花莲县, east Taiwan |
| 光怪陆离 | guāng guài lù lí | monstrous and multicolored; grotesque and variegated |
| 光感应 | guāng gǎn yìng | optical response; reaction to light; light sensitive; photoinduction |
| 光接收器 | guāng jiē shōu qì | optical receiver |
| 光斑 | guāng bān | facula |
| 光明新区 | Guāng míng xīn qū | New Guangming district of Shenzhen City 深圳市, Guangdong |
| 光明星 | guāng míng xīng | bright star; name of North Korean space satellite |
| 光明节 | Guāng míng jié | Hanukkah (Chanukah), 8 day Jewish holiday starting on the 25th day of Kislev (can occur from late Nov up to late Dec on Gregorian calendar); also called 哈努卡节 and simply 哈努卡 |
| 光柱 | guāng zhù | light beam; light pillar (atmospheric optics) |
