1. to talk rubbish/nonsense/crap/bullshit [verb] [ouwehoerde, geouwehoerd] 
"Ouwehoeren" is composed of "ouwe" (from "oud") and "hoer", which translate to "old" and "whore", hence the literal translation would be "to oldwhore"… The related noun "geouwehoer" can be more ore less translated with "old wives chattering", but somehow the old wives ended up has whores in the Dutch language…:-)
"Ouwehoeren" can be used in a negative and positive context, where in the first context it is best translated with "to talk rubbish" (see 1.) and in the latter context with "to chat(ter) (informally)" (see 2.).
Examples:
– "Wat bedoelt Frank daarmee?" – "Let er maar niet op, hij zit te ouwehoeren…"
("What does Frank mean by that?" – "Just don’t pay attention to it, he’s talking rubbish…")
– "Schat, ouwehoer niet zo en schiet op! We moeten nu gaan!!"
("Honey, don’t give me that crap en hurry up! We need to go now!!")
Expressions:
– "Uit zijn nek kletsen": to talk out of the back of one’s neck, to talk nonsense. Lit.: to talk out of one’s neck.
Related words:
– Geouwehoer: rubbish, (load of) crap, bullshit [noun] [het geouwehoer, <no plural>].
Example:
– "De kredietcrisis is de schuld van een wereldwijd financieel-militair complex." – "Geouwehoer!"
("The financial crisis is to be blamed on a global financial-military complex." – "Bullshit!")
– Kletskoek: waffle, twaddle, rubbish (talk), crap [noun] [de kletskoek, <no plural>].
– Kletspraat: waffle, twaddle, rubbish (talk), crap [noun] [de kletspraat, <no plural>].
2. to chat, to chatter, to chit-chat [verb] [ouwehoerde, geouwehoerd]
In a positive context, "ouwehoeren" can be used when chatting while sitting back in a relaxed atmosphere.
Examples:
– "Wat hebben jullie gisteravond gedaan?" – "Een biertje gedronken en lekker geouwehoerd!"
("What did you do last night?" – "Had a beer and just chatted!"
– "Een beetje voetbal kijken en ouwehoeren over buitenspel, dat is wat mannen doen op zondagavond!"
("Just watching some football and chit-chatting about offside, that’s what men do on Sunday night!")
Related words:
– Kletsen: to chat, to chatter, to chit-chat [verb] [kletste, gekletst].
Example:
– "Kinderen! Niet kletsen in de klas!"
("Children! No talking/chatting during class!")
– "Ohaën": (sometimes (incorrectly) spelled as OH-en) short for "OuweHoer-en": to talk rubbish.
There is a *very* informal southern-dutch (Flemish) noun ‘hoerenchance’ which I think is not used in the North. The ‘chance’ part is French for ‘luck’ and is one of the many Gallicisms in southern Dutch, an informal synonym for ‘geluk’.
Literally, ‘hoerenchance’ translates as ‘Whore’s luck’ and it means ‘an exceptionally large amount of luck’. Like in:
“We vonden een parkeerplaats vlak voor de ingang op een zaterdag. Hoerenchance!”
“We got a parking spot right in front of the entrance, on a Saturday. What luck!”
I suppose etymologically it’s origins lie in the fact that whores need a lot of luck not to catch any diseases or get pregnant, especially in older times.