unexpressive
adjective
un·ex·pres·sive ˌən-ik-ˈspre-siv 
1
obsolete : ineffable
2
: not expressive : failing to convey the feeling or meaning intended
Example Sentences
Recent Examples on the Web Redefine masculinity to include expressing their feelings Too often, masculinity and strength have been marked by a stoic, quiet, emotionally unexpressive presentation. 
John Duffy, CNN, 9 Mar. 2021 The term, first meant as an insult, was attached to 1960s abstract artists whose work included hulking monoliths and unexpressive canvasses. Spencer Kornhaber, The Atlantic, 23 Apr. 2020
John Duffy, CNN, 9 Mar. 2021 The term, first meant as an insult, was attached to 1960s abstract artists whose work included hulking monoliths and unexpressive canvasses. Spencer Kornhaber, The Atlantic, 23 Apr. 2020 Word History
First Known Use
1600, in the meaning defined at sense 1