Meaning of “risk” - Learner’s Dictionary

risk

noun uk us /rɪsk/
POSSIBILITY [ C, U ]

B2 the possibility of something bad happening:

the risk of heart disease
People in the Northeast face the highest risk of being burgled.
[ + (that) ] There is a slight risk that the blood could have become infected.
SOMETHING BAD [ C ]

something bad that might happen:

There are more health risks when older women get pregnant.
at risk

B2 being in a situation where something bad is likely to happen:

Releasing these prisoners into the community puts the public at risk.
If you've got asthma, you're more at risk of having eczema.
at your own risk

If you do something at your own risk, you are completely responsible for anything bad that might happen because of it.

run the risk of sth

to do something although something bad might happen because of it:

I think I'll run the risk of hurting her feelings, and tell her the truth.
take a risk

B2 to do something although something bad might happen because of it:

This time I'm not taking any risks - I'm going to get insured.

(Definition of “risk noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)