fly-by-night.
In this phrase, flit is a noun use of to flit, originally used in Scotland and Northern England to mean to move house or leave one's home, especially secretly so as to escape creditors or obligations.
Where does the word flitting come from?
Fleeting comes from the Old English word flēotan, which means “float, swim.” Like a ghost ship floating by on a foggy night, fleeting things disappear as fast as they appear.
What does the Scottish word flitting mean?
In Scots, “to flit” means to move house.
