prefix
Prefix attached to nouns, especially dates, people, companies, schools, and other referents. It can mean 'the same ...' or, in formal and news-style writing, 'the said/aforementioned ...'.
二人は同年に大学を卒業した。
The two graduated from university in the same year.
山田電機は新製品を発表し
Yamada Electric announced a new product, and the company's stock price rose.
unclassified
Terse written use in lists, tables, forms, and similar contexts, indicating that the item is the same as the one just mentioned. This is not the normal spoken word for 'likewise'.
名簿では、二人目の所属欄が「同」になっていた。
In the roster, the second person's affiliation field said 'same as above.'