What does "pigeonholing" mean?

The classification of disparate entities into narrow and often unfair categories.

Pigeonholing

Common synonyms include: analysis, arrangement, cataloging, categorization, categorization, categorize.

noun, verb

noun, verb ·Uncommon ·Advanced level

Noun

1
The classification of disparate entities into narrow and often unfair categories. countable, uncountable
2
a system for classifying things into groups wordnet

Verb

1
present participle and gerund of pigeonhole form-of, gerund, participle, present

"He's skilled at pigeonholing his political opponents' policies as "unamerican.""