When someone says no u and some other guy replies to no u with no u.

1. noun. It is the sudden feeling of an inexplicable joy one gets when something romantic or idealistic occurs.

When kilig, one may experience the following:

*butterflies in one's stomach
*heart melting
*shivers down one's spine
*irrepressible noises from one's mouth
*uncontrollable smiling
*an inner conflict between hope of something wished for and reality

Kilig may also be defined as that mountain top, floating, on cloud nine, invincible, i-could-keep-smiling, heart aching goodness and feeling which overpowers the mind's ability to think straight, act straight, breathe properly and articulate thoughts into a single comprehensible sentence.