Verb (5-dan, く, intransitive)
1.  to float
2.  to become merry;  to be cheerful
3.  to become loose;  to become unsteady
4.  to feel out of it;  to be cut off (e.g. from those around you);  to feel out of place
5.  to be frivolous;  to be uncertain
6.  to have (time, money, etc.) left over;  to be saved (e.g. money)
7.  to have no basis;  to be unreliable