terrace vs patio

terrace and patio both are nouns.

Word	Noun	Adjective	Verb	Adverb
terrace	Yes	No	Yes	No
patio	Yes	No	No	No

As nouns, terrace and patio are synonyms defined as:

terrace (noun)	patio (noun)
usually paved outdoor area adjoining a residence	usually paved outdoor area adjoining a residence
a row of houses built in a similar style and having common dividing walls (or the street on which they face)
a level shelf of land interrupting a declivity (with steep slopes above and below)

terrace (verb)	patio (verb)
make into terraces as for cultivation
provide (a house) with a terrace