IPA: /ˈkɒbˌwɛbi/
KK: /ˈkɑbˌwɛbi/
The most covered with cobwebs; very dusty or neglected.
The old attic was the cobwebbiest place in the house, filled with forgotten items and layers of dust.
Comparative: cobwebbier
Superlative: cobwebbiest
'cobweb' (from Middle English 'coppewebbe', meaning spider web) and '-iest' (a superlative suffix indicating the most). The word 'cobwebbiest' refers to something that has the most cobwebs or is the most covered in cobwebs.
Think of 'cobweb' as a spider's web and remember that 'cobwebbiest' means the most covered in those webs.
No commonly confused words.