Vocabulary

ਹੌਲੇ-ਹੌਲੇ
haule-haule

slowly, gradually, gently (reduplication for emphasis)

adverb
In this song
Still In Love · Jassa Dhillon
Verse 3
ਹੌਲੇ-ਹੌਲੇ ਹੋ ਜੂ ਗਾ ਪਿਆਰ ਦਾ ਸਰੂਰ
haule-haule ho ju ga pyaar da saroor
Slowly the intoxication of love will take over