mediocre [L16th] Mediocre is from Latin mediocris used to mean ‘of middle height or degree’, but literally ‘somewhat rugged or mountainous’, from medius ‘middle’ and ocris ‘rugged mountain’. Medius also gives us medium [L16th] and intermediate [LME], while meridian [LME] goes back to Latin meridianum ‘noon’ from medius dies ‘middle of the day’.