Collaboration, Joint
Noun, する verb, and の adjective
きょうどう
トーフグと日清が、豆腐と河豚味のカップラーメンを、共同開発するらしいよ。
Apparently Tofugu and Nisshin are going to collaborate to make tofu and fugu flavored cup noodles.
トーフグは、北朝せんと共同して、金色の金正日人形を生さんしています。
Tofugu produces golden Kim Jong Il dolls in cooperation with a North Korean firm.
彼は共同の貯金をこっそり使い果たしてしまった。
He secretly used up our joint savings.
People working together on the same thing is cooperation.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.