Imagina acabar con el hambre y la pobreza.
Imagine putting an end to hunger and poverty.
Caption 1, Con ánimo de lucro - CortometrajePlay Caption
The short film titled Con ánimo de lucro starts with a series of commands reminiscent of the John Lennon song "Imagine." But what's that word after Imagina (the familiar command form of imaginar)? The short answer is that acabar means "to end" or "to finish."
Al final... Nuestro caso no es distinto de otros casos que acabaron mal
In the end... Our case is not different from other cases that ended badly
Captions 13-14, Victor & Leo - Recuerdos de amorPlay Caption
Se nos acabaron las galletitas.
We've run out of cookies.
We could end our discussion right there, but we won't because acabar can confuse non-native speakers in a variety of contexts. It's more widely used and has more shades of meaning than its synonym terminar (also "to end"). For example, you'll commonly hear acabar de mean "just" as in:
Con nuestro vino de autor lo acabamos de sacar al mercado y es un Quirus.
With our signature wine we have just put it on the market and it's a Quirus.Play Caption
Acabamos de terminar.
We just finished.
Acabo de enterarme que van a casarse.
I´ve just learned they are getting married.
Meanwhile, acabar por can mean "finally" as in:
Acabé por decirle la verdad.
I finally told him the truth.
Anda, ¡para! ¡ya! ¡Ya está, se acabó!
Come on, stop! Now! That's it, it's over!
Captions 28-29, Carolina - AcentosPlay Caption
¡No irás y se acabó!
You won´t go and that's that!
In some places, especially Argentina, acabar can mean "to have an orgasm," when used in the right context. This usage is colloquial but not considered terribly rude.