בהחלט in English:

Definitely!

I know it's not true, but it definitely seems like the sun revolves around the Earth.

The position of women, over the years, has definitely changed for the better.

This is definitely, 'The good you do for others is good you do yourself'! It's a reward because I was helpful!

There is definitely a way to quit the world and live like an hermit in the mountains, being self-sufficient and without contact with anybody while not dying like a dog.

Look how tipsy she's gotten with just one drink. She definitely can't hold her liquor.

If you have no way to buy food, clothing, accommodation and other such daily necessities, you definitely won't be able to have peace of mind.

Okay, okay, said the doctor. "I'll definitely take a look at her."

He's definitely the right guy for the job. Let him fiddle with a computer and he perks right up.

I can't walk, but I can definitely hobble.

We definitely want to go abroad this summer. Ideally somewhere hot.

‘Was it what you expected?’ ‘Yes, definitely.’ Some old people want help; others most definitely do not.

If you compare the two photos, you can see he is definitely thinner in the earlier one.

"Do you want to come?" "Yes, definitely."

If it doesn't get better after two weeks, you definitely must get a medical exam.

by all means

If you’re applying for a sales-oriented job, where negotiation skills are critical to success, then by all means, demonstrate your negotiating finesse

I'm absolutely fine, by all means.

If you would like to discuss your point, by all means we can do it.

So, by all means, do what it is you have to do.