Hi, first up apologies for any offence caused.

I was hanging around a couple of (rude) girls from Isaan, and a few times this word popped up after I'd said something.

Mang-haa

I'm pretty sure this was it.

Translation?

Well, literally it is hard to translate, but unless I misinterpret your transcription, it is a combination of two words and not Isaan, but Central Thai, although the least polite register.

As I understand it anyway, mâeng แม่ง or แม่-ง is short for แม่มึง mâe mueng. แม่ mâe means 'mother' and มึง mueng is a rude word for 'you'.

hàa ห่า has been discussed here before, it is a type of swear-word and the original meaning is a type of plague/disease [cholera? ].

Could possible be construed as 'May your mama be taken by the plague' or so, but as we know from our own language, with some people, swear words don't necessarily mean all that much in context, they just keep popping out in all situations.

With very tightly knit friends, such swear words can be a way of reaffirming the close status of the people present. In a fight though, the purpose will be intentional insults.

Hi, first up apologies for any offence caused.

I was hanging around a couple of (rude) girls from Isaan, and a few times this word popped up after I'd said something.

Mang-haa

I'm pretty sure this was it.

Translation?

Or maybe it was "Maeng-da" (แมงดา) which is literally a type of crab, but more often used as slang for a pimp or even gigolo!

Maybe thay were referring to you?

Sorry, no offence meant...

yea they probably were referring to me, I could tell by their tone that it wasn't a compliment