Answer:
The question is asking for a comment on "side-street" in the following excerpt from the chapter Seven of The Great Gatsby is an equivalent of "side-street" in the sense of "underhanded," "secret," "sleazy"
Step-by-step explanation:
If we look at the given excerpt, it can be stated that Gatsby and Meyer Wolfsheim are engaged in bootlegging, illegal drug sales, and possibly gambling
Though being on a side-street is not implicating in and of itself, Tom's mockery and choice of words indicate that he is using "side-street" in an ironic or offensive way.
Hence the answer to the given question is that side-street doesn't definitely mean "secret" or "sleazy." but if read the excerpt, one can conclude that here Tom is indicating a secrecy, illegality, and sleaziness.