'internationally-assessed' is a compound formed from 'internationally' + 'assessed'. 'Internationally' derives from 'international' + the adverbial suffix '-ly'; 'international' ultimately comes from Latin elements 'inter-' meaning 'between' and 'natio'/'national' meaning 'birth, nation'. 'Assessed' comes from Latin 'assessare' (frequentative of 'assidere'), where 'ad-' meant 'to/toward' and 'sedere' meant 'to sit'.

'Assess' passed into Middle English via Old French/Anglo-Norman forms and developed legal senses such as 'to determine a tax or value'; 'international' arose in modern English (from 'inter-' + 'national') and the adverb 'internationally' followed. The compound 'internationally-assessed' is a modern English formation used to indicate something evaluated at an international level.

Initially, Latin roots of 'assess' conveyed 'to sit beside' (as a judge); over time the meaning shifted to 'determine value, impose a tax, or evaluate'. 'International' originally described relations 'between nations'; combined, the phrase now specifically means 'evaluated according to international standards or by international bodies'.