'arachnephobia' originates from Greek, specifically the words 'arachne' and 'phobos', where 'arachne' referred to 'spider' (from the mythological name Arachne) and 'phobos' meant 'fear'.

'arachnephobia' is a modern English formation combining Greek roots; it is closely related to the more common variant 'arachnophobia', which is a simplified form that omitted the additional 'e' element.

Initially, it meant 'fear of spiders', and over time this core meaning has remained stable in modern usage.