When it comes to describing a garment that has a low-cut neckline, there are several synonyms that can be used instead of "most low-neck." For example, you might describe a top as having a plunging neckline, a deep neckline, or a v-neckline. Another option might be to use terms like "revealing," "exposed," or "bared" to convey the same idea. In some contexts, the word "decollete" might also be appropriate, especially when referring to formal attire. Ultimately, the choice of synonym will depend on the specific garment in question, the audience, and the tone of the writing or conversation.