godan ~く verb / intransitive verb:

• to float
• to become merry; to be cheerful ➜ 浮かぬ顔
• to become loose; to become unsteady
• to feel out of it; to be cut off (e.g. from those around you); to feel out of place - colloquialism
• to be frivolous; to be uncertain
• to have (time, money, etc.) left over; to be saved (e.g. money)
• to have no basis; to be unreliable