The compound adjective "tenth-century" is a modern English formation that precisely dates a historical period by combining an ordinal number with a standardized time unit. The first element, "tenth," originates from the Proto-Germanic 'tehuntha-', directly linking to the cardinal number ten and signifying position in a sequence. The second element, "century," derives from the Latin 'centuria', a military and administrative term for a group of one hundred, which in Late Latin came to mean a period of one hundred years. The logical construction follows a straightforward pattern where the ordinal number specifies which particular hundred-year block, counted from the conventional start of the Common Era, is being referenced, thus creating a clear and efficient chronological label.

Structure: tenth (ordinal number) + century (period of 100 years) - tenth: From Old English 'tēoþa', related to 'tīen' (ten). An ordinal number suffix derived from the cardinal number 'ten'. - century: From Latin 'centuria', meaning 'a group of one hundred', from 'centum' (hundred). The '-ury' suffix evolved to denote a period or condition.