lãi suất

lãi (“interest”) +‎ suất (“rate”). The word order suggests this is a pseudo-Sino-Vietnamese formation. Perhaps also a non-Sino-Vietnamese reading of Chinese 利率 (SV: lợi luật), by way of replacing the systematic Sino-Vietnamese reading of 利 with the vulgarized one that gave rise to lãi as a common word.

• (Hà Nội) IPA^(key): [laːj˦ˀ˥ swət̚˧˦]
• (Huế) IPA^(key): [laːj˧˨ ʂwək̚˦˧˥] ~ [laːj˧˨ swək̚˦˧˥]
• (Hồ Chí Minh City) IPA^(key): [laːj˨˩˦ ʂ⁽ʷ⁾ək̚˦˥] ~ [laːj˨˩˦ s⁽ʷ⁾ək̚˦˥]

lãi suất

1. (finance) an interest rate

   cho vay lãi suất cao

   to loan at a high interest rate