What does "undergarment" mean?

Any garment worn underneath others, especially one worn next to the skin; an item of underwear.

What is a synonym for "undergarment"?

Common synonyms include: jesus jammies, jesus jammies, skivvies, underwear, unmentionable.

Pronounced //ˌʌn.dɚˈɡɑɹ.mənt//.

//ˌʌn.dɚˈɡɑɹ.mənt// noun

noun ·Rare ·Advanced level

Noun

1
Any garment worn underneath others, especially one worn next to the skin; an item of underwear.
"Richard DeLongpre: Are you okay, my boy angel? Allen Gregory DeLongpre: I have a broken heart. And undergarments filled with my own unruly waste."
2
a garment worn under other garments wordnet
3
Temple garments worn by the followers of the Church of Jesus Christ of Latter-day Saints. in-plural