the word 'sturdy' entered english from old french 'estordi', which meant 'dazed, stunned, or reckless'. this old french term likely derived from the vulgar latin 'exturdītus', meaning 'stupefied', a past participle form related to the latin 'turdus', meaning 'thrush'. the semantic journey is intriguing: from the idea of being stunned like a bird that has been hit, the meaning shifted in english to describe a recklessness or violence in animals, particularly a disease in sheep causing giddiness. from this notion of violent, unsteady motion, the sense evolved by the 14th century to its modern meaning of 'hardy, robust, and strongly built', capturing a strength that can withstand forceful impacts.

the word is a simplex. it is a loanword from old french, where it had the form 'estordi', meaning 'dazed, stunned, reckless'.