An example of expertise is a master gardener's knowledge of gardening.
The scientist has expertise in the field of nuclear fusion.
"Deidre, I'm offering my expertise to assist you," Andre said.
I don't know that we have the expertise here to repair it at this time.
I would not recommend quickly chopping vegetables unless you have expertise with a knife.
I am working on achieving expertise in mathematics so that I can become a teacher.
The timing, the sophistication, the expertise needed to launch such an attack.