Happy birthday

Japanese: 賀 - が

〘noun〙① To rejoice and celebrate. To relax. Celebration. Often used to refer especially to the celebration of longevity. → Celebration of congratulations. ※Kokin (905-914), Congratulations, 347, Preface "A poem sung during the reign of Ninna when Sojo Hensho was congratulated on his 70th birthday" [Book of the Later Han - Etiquette, Vol. 1]② The name of a fragrant wood. It is classified as Manaban . The aroma and flavor are sweet, bitter, and spicy. One of the 61 famous incense sticks. It is said to have been a secret incense of Ashikaga Yoshimitsu, and was used to celebrate his 50th birthday.

ga-suru [ga]

〘Tasahen〙 ga・su 〘Tasahen〙 To express a feeling of joy at something auspicious. To celebrate. To congratulate. ※Taiheiki (late 14th century) verse 18 "We congratulate everyone on the peace and tranquility of the four seas."

GA-SU [Congratulations]

〘Other changes〙 ⇒gasuru (congratulations)

Source: The Selected Edition of the Japanese Language Dictionary About the Selected Edition of the Japanese Language Dictionary Information

Japanese:

〘名〙① よろこび祝うこと。ことほぐこと。祝賀。特に長寿の祝いをいうことが多い。→賀の祝い。※古今（905‐914）賀・三四七・詞書「仁和の御時僧正遍昭に七十の賀たまひける時の御哥」〔後漢書‐礼儀志上〕② 香木の名。分類は真南蛮(まなばん)。香味は甘苦辛。六十一種名香の一つ。足利義満秘蔵の香で、五十の御賀にいたという。