Loosely translated as 'heart' it is combined with other words to express emotions.
Some of my favorite uses for 'jai' are:
jai dee ใจดี happy (heart-good)
dee jai ดีใจ kind (good-hearted)
yen jai เย๊นใจ unfeeling (cool-heart)
rawn jai รัอนใจ hot-blooded (hot-heart)
sia jai เสียใจ sorry (broken-heart)
wai jai ไว้ใจ trusting (keep-heart)
waan jai หวาน sweetheart (sweet-heart)
