Answer:

tip

Answer	Crossword Clue
TIP	Unbalance
TIP	A hot one is timely
TIP	Thank you for waiting

TIP	Gratuity
TIP	What an aglet is for a shoelace
TIP	It's often left on the table
TIP	Word of advice
TIP	Lose balance
TIP	Track advantage
TIP	Good thing coming to those who wait
TIP	Thanks for waiting

TIP	Line on a bill
TIP	Extra 15% or so for a waiter
TIP	Pro ...
TIP	Scratch on the table?
TIP	Bit of advice
TIP	Opposite of stiff
TIP	Money left on the table?
TIP	Lead-in to toe or top

TIP	What an insider might offer
TIP	What boats shouldn't do
TIP	Something worth waiting for?
TIP	Line on a restaurant check
TIP	Line on a restaurant bill
TIP	Informer's info
TIP	Helpful hint
TIP	It might be given to a waiter or a police investigator

TIP	Good thing that comes to those who wait?
TIP	Service award?
TIP	Recommendation
TIP	Scratch left on a table?
TIP	Part of an iceberg that's visible
TIP	Figure just above the total
TIP	Line just above the total
TIP	Show instability

TIP	What to do to hats and waiters
TIP	Visible part of an iceberg
TIP	Not stiff?
TIP	It may be 20%
TIP	Inside info