good vs dependable

good is a noun but dependable is not a noun.

Word	Noun	Adjective	Verb	Adverb
good	Yes	Yes	No	Yes
dependable	No	Yes	No	No

As adjectives, good and dependable are synonyms defined as:

Other synonyms of good include safe, secure.

good (noun)	dependable (noun)
a raw material that is sold in large quantities, usually to other businesses for manufacturing or production purposes
benefit
moral excellence or admirableness
that which is pleasing or valuable or useful

good (adjective)	dependable (adjective)
having desirable or positive qualities especially those suitable for a thing specified	worthy of reliance or trust
morally admirable	financially safe
promoting or enhancing well-being	consistent in performance or behavior
having the normally expected amount	worthy of being depended on
with or in a close or intimate relationship
thorough
generally admired
resulting favorably
not left to spoil
not forged
tending to promote physical well-being; beneficial to health
in excellent physical condition
appealing to the mind
agreeable or pleasing
exerting force or influence
most suitable or right for a particular purpose
capable of pleasing
deserving of esteem and respect
of moral excellence
having or showing knowledge and skill and aptitude
financially safe

good (adverb)	dependable (adverb)
(often used as a combining form) in a good or proper or satisfactory manner or to a high standard (`good' is a nonstandard dialectal variant for `well')
completely and absolutely (`good' is sometimes used informally for `thoroughly')