symbology vs ology

symbology and ology both are nouns.

Word	Noun	Adjective	Verb	Adverb
symbology	Yes	No	No	No
ology	Yes	No	No	No

As nouns, ology is a hypernym of symbology; that is, ology is a word with a broader meaning than symbology:

symbology: the study or the use of symbols and symbolism
ology: an informal word (abstracted from words with this ending) for some unidentified branch of knowledge

symbology (noun)	ology (noun)
the study or the use of symbols and symbolism	an informal word (abstracted from words with this ending) for some unidentified branch of knowledge