More peacockish is a complex phrase that can be broken into two parts; peacockish meaning self-centered and showy, and 'more' meaning increasing that trait. To find the antonyms of this phrase, one needs to look for terms that describe individuals who are modest and do not crave attention. Modest, humble, unpretentious are some antonyms for 'peacockish'. On the other hand, words like restrained, self-effacing, and low-key would be antonyms for 'more'. To create a phrase that can describe the opposite of 'more peacockish,' one may use terms like 'less ostentatious,' 'more humble,' or 'quieter.' Using these words, one can create a description of an individual who is modest and does not seek attention.