ハチ公[hachikou] statue of Hachiko (a dog) at Shibuya station
郭公[kakkou] common cuckoo (Cuculus canorus)
株式公開[kabushikikoukai] stock offering (to the public)
蒲公英[tanpopo] dandelion (esp. species Taraxacum platycarpum)
官公庁[kankouchou] government administration office

丸公[marukou] official price
勤め奉公[tsutomeboukou] apprenticeship
公平[kinpira] chopped burdock root (and sometimes carrot) cooked in sugar and soy sauce
公孫樹[kousonju] ginkgo (Ginkgo biloba)

暗証[anshou] code
暗証化[anshouka] encryption
暗証番号[anshoubangou] personal identification number
証し[shirushi] mark
印鑑証明[inkanshoumei] certification of official registration of a seal

引証[inshou] quotation
仮受取証[kariuketorishou] temporary receipt
会員証[kaiinshou] membership certificate
外国人登録証明書[gaikokujintourokushoumeisho] certificate of alien registration
確証[kakushou] positive proof