fiddle away (something)

to waste time doing nothing in particular.

Billy fiddles away hours on end arranging his model cars.

• knock the stuffing out of someone
• knock the tar out of
• knock the tar out of someone
• knock up
• knock wood
• knock yourself out
• knock your socks off
• know-all
• know a thing or two
• know backwards
• know backwards and forwards
• know beans about
• know beans about something
• know best
• know better
• know better than to
• know better than to do something
• know by heart
• know by sight
• know different
• know from Adam
• know if are coming or going
• know if you are coming or going
• know inside out
• know like the back of hand