bad

feeling physical discomfort or pain (`tough' is occasionally used colloquially for `bad')

my throat feels bad

she felt bad all over

(of foodstuffs) not in an edible or usable condition

bad meat

a refrigerator full of spoilt food

not working properly

a bad telephone connection

a defective appliance

reproduced fraudulently

like a bad penny...

a forged twenty dollar bill

having undesirable or negative qualities

a bad report card

his sloppy appearance made a bad impression

characterized by wickedness or immorality

led a very bad life

feeling or expressing regret or sorrow or a sense of loss over something done or undone

felt regretful over his vanished youth

regretful over mistakes she had made

capable of harming

bad air

smoking is bad for you

physically unsound or diseased

has a bad back

a bad heart

very intense

a bad headache

in a big rage

not financially safe or secure

a bad investment

high risk investments

that which is below standard or expectations as of ethics or decency

take the bad with the good