As nouns the difference between diminutiveness and diminishment
is that diminutiveness is the state or quality of being diminutive while diminishment is the act of diminishing; reducing in size, quantity, or quality.
diminutiveness
English
Noun
(-)
The state or quality of being diminutive.
diminishment
English
Noun
(
en noun)
The act of diminishing; reducing in size, quantity, or quality.