Z
M
J
K
O
100

Zero hour 

a time when a crucial decision or essential action must be taken  

100

make all the difference 

influence someone or something in a positive way

100

jump on the bandwagon 

to start doing something because it is fashionable or profitable

100

king of the hill 

be the undisputed champion  

100

on top of the world 

in a good mood as everything is going well for you  

200

Zoning out

Not paying attention

200

more than meets the eye 

not as simple as it looks  

200

jump to conclusions

to predict a situation without having sufficient information

200

knotty problem

difficult or complex problem

200

out of hand

out of control  

300

zip your lip

to stop talking  

300

mull over 

to take a long time to make a decision  

300

jump the gun

start something too soon or early, especially without thinking

300

kick the habit 

to overcome an addiction  

300

outside the lines

not sticking to the rules  

400

zip past 

to move past (someone or something) very fast  

400

mind your own business 

to look into your own matter  

I would like you to mind your own business and stop telling me what to do.  

400

just deserts 

get what one deserves

 After the supervisor was suspended, many workers felt that he got his just deserts  

400

knock socks off 

doing something which was never done before 

 Lara's performance at the concert last night just knocked my socks off.  

400

old school

old fashioned ideas or approach compared to current trends  

500

zero tolerance 

enial to allow rebellious activities, usually by rigid and strict application of the rules;  

500

Music to ears

something that is soothing to your ears  

500

Jack of all trades 

someone who is competent at many things but does not excel at any of them  

500

kick the can down the road 

to avoid dealing with a problem  

500

on edge

to feel tense or unable to relax