To gradually reduce in intensity or amount; to diminish or fade away.

कम होना / धीरे-धीरे समाप्त होना

English Usage: The sound of the music began to tail away as the night ended.

Hindi Usage: संगीत की ध्वनि रात के खत्म होते-होते कम हो गई।

The rear part of an animal's body, often extending from the spine.

पूंछ

English Usage: The dog wagged its tail in excitement.

Hindi Usage: कुत्ते ने उत्साह में अपनी पूंछ हिलाई।