'tree-worshipper' originates from English, specifically a compound of 'tree' and 'worshipper', where 'tree' referred to a woody plant and 'worshipper' is an agent noun formed from 'worship' meaning reverence.

'tree' comes from Old English 'trēow' meaning 'tree' or 'wood'; 'worship' comes from Old English 'weorþscipe' meaning 'worthiness' or 'honor', which developed into 'worship'; adding the agent suffix '-er' produced 'worshipper', and the compound 'tree-worshipper' formed in modern English by combining 'tree' + 'worshipper'.

Initially, 'worship' (from 'weorþscipe') meant 'worthiness' or 'honor', but over time it evolved to mean acts of reverence or religious devotion; 'tree-worshipper' therefore denotes someone showing reverential devotion to trees.