IPA: /ˌæntiˈbɪlˌbɔrd/
KK: /æntiˈbɪlˌbɔrd/
Describing something that is against or opposes the placement of advertising billboards.
The community organized an antibillboard campaign to protect the natural landscape.
Antibillboard is formed from "anti-" (meaning against) and "billboard" (a compound word where "bill" refers to a notice or advertisement and "board" refers to a flat surface). The word describes something that is against or opposes the use of billboards for advertising.
Think of 'anti-' meaning against, and 'billboard' as a surface for advertisements. This helps you remember that 'antibillboard' refers to something that opposes advertisements on billboards.