余裕（yoyuu) is a great word to learn in Japanese because it has no direct translation to a word in English with the same nuance, and also because you’re likely to hear in in daily life once in awhile.
Generally speaking, 余裕 represents some sort of resource, and oftentimes it is used in the negative sense to specify that resource is lacking.
It’s uses can be broken up into four broad categories: space, time, money, and emotion. I’ll go over an example of each so you can see the usage.
- I have no space to put (that) in my room.
- Today I was very busy and had almost no time to relax.
- I don’t have (much) money and might not be able to afford a new car.
This usage is the hardest to understand and the most difficult to translate to English. You can think of it as a mental energy, or “bandwidth” of sorts.
- He defeated his enemy with ease.
I have a strange memory where at times I can forget important things, but sometimes I can clearly remember the first time I heard a Japanese word. This is true for 余裕 – I first heard it playing an old Playstation snowboarding game called ‘SSX’. There was a Japanese character, and when she did some great trick she yelled “余裕! 余裕!” which I now understand is similar to the last example above, and basically means she was bragging about how easily she outdid the other participants.