Final answer:
The best meaning of the word 'diminutive' in the context given is 'small or unimportant'. It refers to something small in size, and sometimes, when used for names, it reflects endearment.
Step-by-step explanation:
The word diminutive can be best defined as 'small or unimportant' when looking at the options provided. Despite its negative connotation, it often refers to something that is small in size rather than in worth or importance. In terms of endearment, a diminutive form of a name, for instance, often expresses familiarity or affection, but it is not the primary meaning of the word.