'dendrogram' originates from Greek, specifically the words 'dendron' and 'gramma', where 'dendron' meant 'tree' and 'gramma' meant 'something written or drawn'.

'dendrogram' was formed in modern scientific usage by combining Ancient Greek roots; the compound was adopted into New Latin/English scientific vocabulary in the late 19th to early 20th century and entered English as a technical term in fields such as botany, phylogenetics, and statistics.

Initially built from roots meaning 'tree' + 'written/drawn', it came to mean specifically a 'tree-like diagram' representing relationships or hierarchical clustering and has retained that technical sense.