stimulate: [16] Latin stimulus denoted a ‘pointed stick for goading animals on’ (it probably came ultimately from an Indo-European base *sti- ‘point, prick, pierce’, extensions of which lie behind English stick, stitch, style, etc). It was used metaphorically for ‘something that incites or causes a response’, and in that sense was borrowed into English as stimulus [17]. Stimulate itself comes from the past participle of the derived verb stimulāre ‘goad on’. => stick, stitch, style