Superlative form of frilly; having the most frills or being the most elaborately decorated with frills.
Superlative form created by adding '-est' to 'frilly.' English adjectives typically use '-est' for superlatives (instead of 'most') when they're one or two syllables.
Superlatives in English often involve unpredictable spelling changes—'frilly' becomes 'frillier' and 'frilliest,' but notice how English keeps those double-l's. Some adjectives double their final consonant (run→runner→runniest) while others don't; it's one of English's quirky phonetic rules.
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