hẹn gặp lại

hẹn +‎ gặp +‎ lại.

• (Hà Nội) IPA^(key): [hɛn˧˨ʔ ɣap̚˧˨ʔ laːj˧˨ʔ]
• (Huế) IPA^(key): [hɛŋ˨˩ʔ ɣap̚˨˩ʔ laːj˨˩ʔ]
• (Saigon) IPA^(key): [hɛŋ˨˩˨ ɣap̚˨˩˨ laːj˨˩˨]

hẹn gặp lại

1. see you later; see you

• Similar to cases like chào buổi sáng, hẹn gặp lại is used more as a translation of the English phrase see you later than an actual Vietnamese phrase. More natural equivalent expressions would be gặp (lại) sau nhé/nha or simply sau nhé/nha.
• For the casual English see you, expressions such as chào nhé/nha or bai nhé/nha would be closer in usage.