a unit of currency in Britain and many other countries, worth 100th of a pound
a bronze coin representing a former British monetary unit worth 240th of a pound
NAmer, informal a cent
a denarius
(in negative contexts) the least amount of money
He didn't have a penny
a penny for your thoughts
used to ask somebody what they are thinking about
be ten/two a penny
chiefly Brit to be very common or plentiful and therefore worth little
the penny drops
chiefly Brit, informal the true meaning finally dawns
[with reference to coin-operated machines worked by putting a penny into a slot, which drops to activate a mechanism][Old English penning, penig]