WORD ORIGIN

Late Middle English (also in the sense ‘press out, obtain by squeezing’, used figuratively to mean ‘extort’): from Old French expresser, based on Latin ex- ‘out’ + pressare or premere ‘to press’; express meaning ‘intended for a particular purpose’ is from another Latin word primere ‘to press’—the source of express train and other uses that involve high speed

These lists include all word families of both of the stems above.
air-express,  expresser,  expressional,  expressionistic,  expressionlessness,  expressivity,  inexpressive,  inexpressiveness,  misexpress,  misexpressed,  misexpression,  neo-expressionism,  neo-expressionist,  overexpress,  overexpressed,  overexpression,  re-express,  re-expression,  self-expressive,  self-expressive,  unexpressive,  well-expressed
Only available upon request
Only available upon request