'spiky' originates from the word 'spike,' which comes from Old English 'spīca,' meaning 'ear of grain.'

'spīca' transformed into the Middle English word 'spike,' and eventually became the modern English word 'spike,' with 'spiky' as a derivative adjective form.

Initially, it referred to 'an ear of grain,' but over time it evolved to describe anything with sharp points or spikes.