Linguistics

Another rather counter-intuitive cognate for both is "cycle". It looks nothing like either, and it's the result of

• PIE *kʷékʷlos →
• inherited: Ancient Greek ⟨κύκλος⟩ [kúklos]→[kyklos] →
• borrowed: Latin as ⟨cyclus⟩ [kʏklʊs], accusative ⟨cyclum⟩ [kʏklʊ̃]. That [ʏ] only applies to erudite pronunciation, most folks likely used [ɪ].
• [re]borrowed: French as ⟨cycle⟩ *[siklə] (modern pronunciation [sikl] ).
• borrowed: English as ⟨cicle⟩~⟨cycle⟩ [si:klə]→[saɪ.k(ə)l].

The French step is disputable, as it's also possible that English got the word from the same source as French, straight from the Ecclesiastical pronunciation; that would explain the lengthened vowel. Either way, French certainly reborrowed the word, it cannot be inherited otherwise the vowel would be [e].