This is the 16664th most frequent Russian word.
сигнализирует
"Signals" or "indicates."
In this sentence, 'сигнализирует' refers to the action of the lighthouse sending physical or visual signals as a warning or guidance to ships.
Маяк сигнализирует кораблям о приближении к берегу.
The lighthouse signals ships about approaching the shore.
Here, 'сигнализирует' is used to express the concept of indicating or providing clues about an internal state, in this case, through behavior.
Ее поведение сигнализирует о стрессе или тревоге.
Her behavior signals stress or anxiety.
In this usage, 'сигнализирует' conveys the action of announcing or marking the beginning of an event through a specific sound.