Full Idea
Three interrelated features of vague predicates such as 'tall', 'red', 'heap', 'child' are that they have borderline cases (application is uncertain), they lack well-defined extensions (objects are uncertain), and they're susceptible to sorites paradoxes.
Gist of Idea
Vague predicates involve uncertain properties, uncertain objects, and paradoxes of gradual change
Source
R Keefe / P Smith (Intro: Theories of Vagueness [1997], §1)
Book Reference
'Vagueness: a Reader', ed/tr. Keefe,R /Smith,P [MIT 1999], p.2
A Reaction
The issue will partly depend on what you think an object is: choose from bundles of properties, total denial, essential substance, or featureless substance with properties. The fungal infection of vagueness could creep in at any point, even the words.