miniatureyoudaoicibaDictYouDict[miniature 词源字典]
miniature: [16] ‘Smallness’ is a purely secondary semantic development as far as miniature is concerned, inspired by its accidental similarity to the min- element of words like minimum and minute. It in fact comes ultimately from Latin minium ‘red lead’. Red lead was used in ancient and medieval times for making a sort of red ink with which manuscripts were decorated, and so the derived medieval Latin verb miniāre was coined for ‘illuminate a manuscript’.

Italian took this over as miniare, and derived miniatura ‘painting, illustrating’ from it. It referred particularly to the small paintings in manuscripts, and when English borrowed it as miniature it was soon broadened out to any ‘small image’. Association with minute, etc led by the early 18th century to its adjectival use for ‘small’.
[miniature etymology, miniature origin, 英语词源]
miniature (n.)youdaoicibaDictYouDict
1580s, "a reduced image," from Italian miniatura "manuscript illumination or small picture," from past participle of miniare "to illuminate a manuscript," from Latin miniare "to paint red," from minium "red lead," used in ancient times to make red ink, a word said to be of Iberian origin. Sense development is because pictures in medieval manuscripts were small, but no doubt there was influence as well from the similar-sounding Latin words that express smallness: minor, minimus, minutus, etc.
miniature (adj.)youdaoicibaDictYouDict
"small," 1714, from minature (n.). Of dog breeds, from 1889. Of golf, from 1893.