Monkey nuts are another name for the peanut. It is also known as earthnuts, ground nuts, goober peas, monkey nuts, pygmy nuts and pig nuts.
They are eaten all around the world in various guises and flavours.
So can guinea pigs eat monkey nuts?

Unfortunately they can’t.
It is common knowledge that guinea pigs can’t eat peanuts, but what is the reason for this. Lets take a look at its nutritional data and find out why it is so bad for them.
Carbohydrates 21 g
– Sugars 0.0 g
– Dietary fiber 9 g
Fat 48 g
– saturated 7 g
– monounsaturated 24 g
– polyunsaturated 16 g
Protein 25 g
– Tryptophan 0.2445 g
– Threonine 0.859 g
– Isoleucine 0.882 g
– Leucine 1.627 g
– Lysine 0.901 g
– Methionine 0.308 g
– Cystine 0.322 g
– Phenylalanine 1.300 g
– Tyrosine 1.020 g
– Valine 1.052 g
– Arginine 3.001 g
– Histidine 0.634 g
– Alanine 0.997 g
– Aspartic acid 3.060 g
– Glutamic acid 5.243 g
– Glycine 1.512 g
– Proline 1.107 g
– Serine 1.236 g
Water 4.26 g
Thiamine (vit. B1) 0.6 mg (52%)
Niacin (vit. B3) 12.9 mg (86%)
Pantothenic acid (B5) 1.8 mg (36%)
Vitamin B6 0.3 mg (23%)
Folate (vit. B9) 246 μg (62%)
Vitamin C 0.0 mg (0%)
Calcium 62 mg (6%)
Iron 2 mg (15%)
Magnesium 184 mg (52%)
Phosphorus 336 mg (48%)
Potassium 332 mg (7%)
Zinc 3.3 mg (35%)
(source: Wikipedia)
As you can see, monkey nuts are really bad for guinea pigs for the following reasons;
With all these factors, monkey nuts are a real no-go for guinea pigs.
If they happen to nibble on one, they should be fine but they should not be fed to guinea pigs purposely.