[AlaninCarlisle]

The following words are still occasionally used by my wife and me. They have survived the forty-odd years since our children first coined them.
Ya-ya = Lorry
Combinister = Combine harvester
Beebana = Banana
Beemarto = tomato
Norange = Orange
Wocky = warm woollen top or electric blanket
Coromonation Street= Coronation Street

What about your families?

[Fairy Plotmother]

Biffers    = slippers
laller      = ladder
radigator = radiator
sure there's more!!!!!

[Lardman]

Schnappoo - Shampoo

[oldgrunge]

Sad beans - Sardines
Messamade - Lemonade
And a couple that are Welsh -
Ty bydyr ( dirty house) - ty gwydyr (Greenhouse)
Wy mewn pot ( egg in a pot) - Boiled egg

[wighty]

egg in a cup - boiled egg
mucked up egg = scrambled egg
bolly - umbrella

again I'm sure there's a few more.  Will ask the girls over the weekend what they remember and still use.

[Goosegirl]

Rootit - that was me trying to say Rupert Bear and it's the only one I can remember.
Since being together my OH and I have made up our own, such as:-

Dentures - from aperitif (a pair of teeth).
Quickie - a quiche (no Growster, no).
Scrapy pots - boiled potatoes with their skin scraped off.
 

[madcat]

Fizz - sieve  (I've even asked for a fizz in a kitchen shope  )
tundish - funnel  (I think that might be my brewer dad ...)

[AlaninCarlisle]

Tundish in an accepted word in Lancashire for a funnel. We use it all the time

[mrs bouquet]

Nany-noos - Bananas.    Mrs Bouquet

[John]

Heeyah - from here you are

[Growster...]

Candles - runny nose,
Bemato (interesting you have that one, Alan)!
Rooterp - the bear...

My dad used shorkwop a lot (workshop)...