Numbers give meanings

One sided : partial, unfair
One way : requiring no reciprocal action
First aid : emergency treatment before the regular medical
treatment available
One-off : only happening once
One-horse town : a small, old fashioned and boring town
One-liner : a short joke, a funny remark
First footer : the first person to enter a house in the New Year
Second banana : a person in a subservient position
Two-faced : double-dealing, false
Two-way street : situation, depends on co-operation of two people
Three-ring circus : a confused situation due to too much activity
Third party :someone who is not one of the two main people
Fourth dimension : time
Four-eyes : one who wears glasses
Four-flusher : someone who cheats others
Fifth column : a group of people who work secretly for the enemy
Fifth wheel : one who is superfluous, unnecessary or burdensome
To take five : to stop working for a few minutes
At sixes and sevens : in utter confusion or disorder
In seventh heaven : to be supremely happy
Behind the eighth ball : in a highly disadvantageous or dangerous position
On cloud nine : to be extremely happy
Dressed (up) to the nines : wearing the best or most formal clothes
Ten to one chance : very probably
Be ten a penny : a dime a dozen, to be very common, not unusual
Ten-strike : a stroke of great success, a very profitable bargain
Eleventh hour : at the last possible moment, just in time
Talk nineteen to the dozen : to talk very quickly and without stopping
Forty winks : a short sleep, esp. after dinner
Go fifty-fifty : share the cost of something equally
Hundreds of : a lot of
Wife in a thousand : a perfect wife
Look like a million dollars : to look very attractive
On somebody’s last legs : to be very ill, likely to die soon