。
Looks like dinner's going to be late.
Literal
Dinner [topic-は] late become-[appearance-ようだ].
ようだ ('seems, looks like') is a higher-certainty evidential than そうだ — it's based on broader, more deliberate evidence rather than a fleeting visual impression. 遅くなる ('to become late, to run late') uses the [adjective-く + なる] pattern for change of state. A small register step up from the more impressionistic そうだ feels.