Quick answer
hombre
Natural: come on / oh come on / well
Literal: “man”
How it is used
¡Hombre, claro!Well, of course!
Hombre, no exageres.Come on, don’t exaggerate.
¡Hombre, cuánto tiempo!Hey, it’s been ages!
Hombre, yo lo veo distinto.Well, I see it differently.
Where it is said
It is heaviest in Spain, where it is said to women and men alike; many Latin American speakers reach for <b>oye</b> or <b>che</b> in Argentina instead.
A mini dialogue
— ¿Te apetece un café?— Do you fancy a coffee?
— ¡Hombre, por supuesto!— Well, of course!
Watch out
hombre
Do not read it as a gendered address; hombre here is an interjection and says nothing about who you are talking to.
Check yourself
What does “Hombre, no exageres” express?