free lunch

eat someone's lunch

To best or defeat someone thoroughly; to make short work of.

feel free

To feel able without giving offense.

free hand

Synonym of free rein.

free ride

An opportunity or benefit which has no cost, especially one enjoyed or undertaken at the expense of others.

get out of jail free card

A certain privilege or advantage that provides relief from an undesirable situation or immunity from punishment or consequences.

go free

To go or travel where one wishes; to not be kept in custody or confinement.

out to lunch

Clueless, inattentive, or careless.

power lunch

A working lunch at which bosses make business decisions or hold important discussions.