IPA: /ˈfɔːr.tɪs.laɪk/
KK: /ˈfɔrtəslɪk/
Having a shape or quality similar to a fortress, often implying strength and protection.
The building was designed to be fortresslike, with thick walls and few windows.
Fortresslike → It is formed from "fortress" (from Latin *fortis*, meaning strong) and "-like" (meaning resembling or similar to). The word "fortresslike" describes something that resembles or has the qualities of a stronghold or fortified place.
Think of a 'fortress' being 'strong' and 'like' something else — that's why fortresslike means resembling a stronghold.