This is the 4502nd most frequent Japanese word.
寂しい
Lonely; sad; desolate.
Expressing a feeling of loneliness and missing companionship.
最近、友達とあまり会えなくて寂しいです。
Lately, I feel lonely because I can't meet my friends often.
Indicating anticipated feelings of loneliness brought by someone's absence.
彼がいなくなると寂しくなるだろう。
I will probably feel lonely if he leaves.
Describing a melancholic feeling about a seasonal change, not necessarily tied to people.