This is the 7999th most frequent Japanese word.
天皇
"天皇" (Tennō) means "Emperor of Japan."
In this sentence, '天皇' is used to refer to the Emperor as a symbolic figurehead of Japan, signifying the cultural and ceremonial role they play.
天皇は日本の象徴です。
The Emperor is a symbol of Japan.
Here, '天皇' is used in the plural context, referring to the historical succession of emperors through time.
歴史には多くの天皇が登場します。
Many emperors appear throughout history.
In this instance, '天皇' refers to the specific current Emperor, and '天皇陛下' adds an honorific indicating respect for their position.