during

\ \ [14] During, like durable [14], durance [15], duration [14], duress, and endure [14], comes ultimately from the Latin adjective dūrus ‘hard’. This goes back to an earlier *drūros, which is related to Irish dron ‘solid’, Lithuanian drūtas ‘strong, solid’, and Sanskrit dāruna- ‘strong, hard’, and links with Irish daur ‘oak’ (a possible relative of druid) and Greek drus ‘oak’ suggest that its original underlying meaning was ‘oak wood’, from which ‘hard’ developed as a metaphorical extension. The Latin verb dūrāre meant originally literally ‘harden’, but this widened (perhaps with memories of an underlying sense ‘strong, resilient’) to ‘continue in existence, last’. It is these notions of ‘continuance’, ‘strength’, and ‘perseverance’ that emerge in different proportions in durable, duration, and endure, and indeed in during, which is a translation of Old French durant, the present participle of durer ‘last’: phrases such as ‘during the day’ mean etymologically ‘as long as the day lasts’. Durance, an archaic term for ‘imprisonment’, originally denoted ‘length of sentence’, and so is virtually equivalent to the modern ‘for the duration’.

\ \ Cf.⇒ DURABLE, DURATION, DURESS, ENDURE