欢聚一堂 (huān jù yī táng) — Gathered Joyfully Under One Roof · Everyone Came · One Hall, One Evening

Open 《说文解字》 (c. 100 CE) at the 欠 section and every entry in it is something done with the mouth open: 歌 to sing, 欲 to want out loud, and 欢 (歡) among them, glossed simply 喜乐也. 欠 itself is drawn there as 张口气悟也，象气从人上出之形 — a mouth opening, breath rising and leaving a person. But the more useful fact about 欢 is not that it is loud; it is that it always has a second party. 欢迎 is gladness pointed at someone arriving, 欢送 the same gladness pointed at someone leaving, 联欢 gladness held jointly. There is no 欢 you can do by yourself. The character carries its audience inside it.

聚 was once a place you could walk to. 《说文》 reads it 会也, to convene, and builds it on 乑 — three human figures standing side by side — then ends the entry with 邑落云聚: a hamlet is called a 聚. 《史记·五帝本纪》 shows the word doing exactly that work in its account of Shun: 一年而所居成聚，二年成邑，三年成都 — in one year the place he settled became a 聚, in two a town, in three a city. Convergence in this character was never abstract. People came to where somebody was, and what they made by coming had a name and a location.

The last two characters are the ones that do the quiet work. 堂 is not a generic room: it is the raised main hall of a Chinese house, built up on packed earth — hence the 土 beneath it — and it is where guests are received and rites are held, as opposed to 室, the inner chamber where the family actually lives. Confucius grades a disciple on that architecture in 《论语·先进》, saying the man has ascended to the 堂 but not yet entered the 室. So 一堂 does not mean one household. It means everyone in the receiving hall, the room a family opens to visitors — which is why the phrase has never required the people in it to be kin. The four characters together are a late formation — not a line lifted from any classic, but a vernacular phrase assembled from old parts on a frame Chinese had already worn smooth: 济济一堂, a hall packed with worthies, runs on exactly the same pattern. What 欢聚一堂 adds is the condition, and it is a modest one. Not that the room be full of the accomplished. Only that the people in it be glad they came.

• 人生不相见，动如参与商。今夕复何夕，共此灯烛光。

  《赠卫八处士》杜甫 (Du Fu, "For Wei the Eighth, Who Lives in Retirement," 759)
  In this life we go without seeing one another, moving like Shēn and Shāng — the two stars that never share a sky. What night is this night, that we sit together under one lamp? — Du Fu had just found a friend he had not seen in twenty years, in the middle of the rebellion that scattered everyone he knew. The most quoted line in the poem is not about the reunion but about its improbability: he names two constellations that rise only once the other has set, then asks what night it can possibly be. The greatest gathering poem in the language spends its opening explaining why the evening should not have happened.

• 而浮生若梦，为欢几何？古人秉烛夜游，良有以也。

  《春夜宴从弟桃花园序》李白 (Li Bai, "Preface to a Spring Night Banquet with My Cousins in the Peach Blossom Garden," 8th c.)
  This floating life is like a dream — how much of it is gladness? The people before us walked at night holding candles, and they had good reason. — Li Bai wrote this as the note explaining a party, and the word he uses for the gladness being counted is 欢 itself. It is the plainest argument in Chinese for why gatherings get held at all: the quantity is small and finite, so you do not put the evening off to a better month.

• 宴酣之乐，非丝非竹，射者中，弈者胜，觥筹交错，起坐而喧哗者，众宾欢也。

  《醉翁亭记》欧阳修 (Ouyang Xiu, "The Old Toper's Pavilion," 1046)
  The joy of a feast at its height is not in the strings and not in the flutes: the archer hits his mark, the chess player wins, wine cups and tally sticks crisscross the table, and people are up and down and making a racket — that is the guests being glad. — Ouyang Xiu defines the pleasure of a gathering by ruling out the entertainment he laid on for it. What he keeps is the crowd itself, and the character he lands on to name what they are doing is 欢.

The program watched by more people than any other on the night it airs is named for the first of these four characters. 春节联欢晚会 — the Spring Festival Gala, broadcast every Lunar New Year's Eve since 1983 — is the Spring Festival joint-欢 evening party, and 联欢 has been an institution word in modern Chinese ever since: the 联欢会 is what a school, a factory, or a work unit calls the evening it sets aside for its own people. Chinese marks both doors of such an evening with the same character too. You are 欢迎 on the way in and 欢送 on the way out, met with gladness and sent off with it, and what happens between the two doors is the phrase on the banner.

What the phrase will not do is pretend the evening lasts. Chinese keeps 聚散 — gathering and scattering — as a single standing word, because nobody ever expected the halves to come apart, and the proverb every family can finish is 天下没有不散的筵席: no banquet under heaven fails to break up. 一堂 is one hall and one night, and the phrase says so in its own last two characters. That is what separates it from the blessings it hangs beside, which mostly ask for a condition to hold: a household in accord, a life come out whole, a line still flourishing in fifty years. 欢聚一堂 asks for nothing to hold. It concedes at the start that everyone goes home tomorrow, and says the evening counted anyway — which is precisely why it gets brushed onto paper, where the evening cannot.