wild
The word "erratic" is an adjective. It is used to describe something that is unpredictable or irregular in behavior or movement.
erratic
random
The word erratic is an adjective.
volatile: flighty, unpredictable
The word 'erratics' is a plural noun; the plural form of the noun 'erratic', a word for a rock that differs from the rock surrounding it, believed to have been deposited by glacial action; a word for a thing.
The word 'erratic' is a noun related to geology; a word for a large rock that does not match the rocks or rock formations in its surroundings and is believed to have been deposited by glacier.More commonly, the word 'erratic' is an adjective, a word used to describe a noun, for example, erratic behavior or erratic weather.
Not entirely certain but, I would say from the definition of the word erratic, erratic rainfall refers to unpredictable rainfall. Non-uniform rainfall. Like when you know its rainy season but the weather forecast says there would be little or no rainfall. You leave the house and get dripping wet after 5 minutes of rain! Reminds me of the Nigerian meteorological services (Weather forecasting corporation)
The meaning of "fitful" is something having a spasmodic character, or something recurring irregularly. Words with a similar meaning to the word include broken, disturbed, erratic, etc.
A prefix is added at the beginning of a word.
The root word of unpredictable is "predict."
http://thesaurus.reference.com/browse/beginning