One way to picture gregarious: something that is almost never found alone. Deer move as a herd, birds feed as a flock, small mushrooms come up twenty at a time, and the same word gets turned on the person who walks into a room and heads for the fullest table. Wherever it goes, it points at one habit — being with others rather than apart.
From the word’s history
The supplied source records only that English borrowed this word from Latin gregārius, first attested 1688. The same entry separately lists an older, plain sense: pertaining to a flock or crowd. That older sense sits closest to the group picture. The source does not gloss the Latin word itself, so nothing further is claimed here.
來源資料只記到：1688 年左右借自拉丁文 gregārius。同一份資料另外收了一個較舊的意思——「跟一群、跟群體有關」。這個舊意思跟上面那幅「成群」的畫面最接近。至於拉丁原字本身怎麼解釋，資料沒有寫，這裡也就不多說。
Wiktionary entry supplied in the evidence packet (source_ref kaikki:3f6f69a190036ae4:209369552)
登入就可以看每一支怎麼連回核心畫面。