- a small comparatively cheap digital computer 
WordReference Random House Learner's Dictionary of American English © 2025
min•i•com•put•er /ˈmɪnikəmˌpyutɚ/USA pronunciation  
n. [countable]
WordReference Random House Unabridged Dictionary of American English © 2025- Computinga computer with processing and storage capabilities smaller than those of a mainframe but larger than those of a microcomputer.
min•i•com•put•er 
(min′ē kəm pyo̅o̅′tər),USA pronunciation n. 
- Computinga computer with processing and storage capabilities smaller than those of a mainframe but larger than those of a microcomputer, used by small businesses, in manufacturing processes, in scientific research, etc.
- mini- + computer 1965–70
Collins Concise English Dictionary © HarperCollins Publishers::
'minicomputer' also found in these entries (note: many are not synonyms or translations):