Give someone the go-by is the idiom equals to ignoring someone or avoid someone intentionally. Nevertheless, there are many synonyms that can be used as a substitute for this phrase. Snub someone, brush off, disregard, neglect, slight, shun, reject, bypass, evade, overlook, turn one's back on, pass up, and ostracize are some words that can be interchangeably used in this context. These words indicate an act of ignoring someone or avoiding someone intentionally. By using one of these synonyms, the speaker can communicate effectively about such rude behavior towards the individual.