trống

• (Hà Nội) IPA^(key): [t͡ɕəwŋ͡m˧˦]
• (Huế) IPA^(key): [ʈəwŋ͡m˦˧˥]
• (Hồ Chí Minh City) IPA^(key): [ʈəwŋ͡m˦˥]

Probably from Old Chinese 孔 (OC *kʰloːŋʔ) (SV: khổng).

trống • (𥧪, 𥨨)

1. empty; vacant

Cognate with Tho [Cuối Chăm] kʰrɔːŋ³. Compare sống as in the compound sống mái.

The form sống was attested in numerous texts written in the Northern dialects well into the early 20th century, although just primarily in gà sống. The ‹s-›-‹tr-› correspondence indicates that the now dominant form trống originated from the North Central region (compare pairs such as sừng vs. trừng (“horn”), sâu vs. trâu (“caterpillar”), sành vs. trèng (“terracotta”)).

• (Northern Vietnam) sống

trống • (𪟤, 𩀳)

1. (of a bird) male

   Antonym: mái

   gà trống ― a rooster

2. (of an animal with cá (“fish”) in its name, including cetaceans) male

   Antonym: mái

   cá heo trống/đực ― a male dolphin

• Less common than đực when used for "fish", although it is not rare nor uncommon.

• đực

Borrowed from Tai. Compare Thai กลอง (glɔɔng) and Lao ກອງ (kǭng).

(classifier cái, chiếc) trống • (𤿰, 𫪹, 𪔠, 弄, 𲎚)

1. (music) drum

• "trống" in Hồ Ngọc Đức, Free Vietnamese Dictionary Project (details)