'Thuja' originates from New Latin 'Thuja', ultimately from Greek 'thuia' (θυία), a name for a tree used in fragrant smoke and sacrificial rites.

'Thuja' was taken into botanical Latin (New Latin) as the genus name by early taxonomists (Linnaean era); the Greek 'thuia' passed into Latin usage and then into modern scientific nomenclature as 'Thuja'.

Initially, the word referred broadly to a fragrant or sacrificial tree in ancient Greek usage; over time it became the specific botanical name for this genus of evergreen conifers.