Adolescence /ˌæd

onset /ˈɒn.set/ /ˈɑːn-/ noun
the onset of sth
the moment at which something unpleasant begins
the onset of cancer
The new treatment can delay the onset of the disease by several years.
portion /ˈpɔː.ʃ ə n/ /ˈpɔːr-/ noun [ C ]
1. a part or share of something larger
A large/major portion of the company's profit goes straight back into new projects.
I accept my portion of the blame.
2. the amount of a particular food that is served to one person, especially in a restaurant or a shop which sells food ready to be eaten
The portions are very generous in this restaurant.
risk /rɪsk/ noun
1. [ C or U ] the possibility of something bad happening
In this business, the risks and the rewards are high.
There's a high risk of another accident happening in this fog.
[ + ( that ) ] The risk (that) we might fail made us work twice as hard.
[ + -ing verb ] It's always a risk start ing up a new business.
The company is quite a good risk (= safe to lend money to) .
We want clean rivers and lakes, where you can swim without risk to your health.
It's a low/high- risk strategy (= one that is safe/not safe) .
2. [ C ] something bad that might happen
This wire is a safety/fire risk.
His employers thought he was a security risk (= he might tell their secrets to a competitor) .
3. at risk
in a dangerous situation
All houses within 100 metres of the seas are at risk of flooding.
4. at your own risk
used to mean that you are responsible for any damage, loss or difficulty
Owners are reminded that they leave their cars here at their own risk.
5. run/take a risk
to do something you know might be dangerous
Don't take any risks - just ring the police.
serving /ˈsɜː.vɪŋ/ /ˈsɝː-/ noun [ C ]
an amount of one type of food which is given to one person
The quantities given in the recipe should be enough for four servings.