There are several synonyms for the phrase "be nearby" that can be used to convey a similar meaning. One such synonym is "be close," which suggests proximity or proximity within reach. Another possible synonym is "be adjacent," implying proximity or adjacency in space or time. "Be in the vicinity" could also be used to convey a sense of proximity or proximity to a specific location. Other possible synonyms include "be in close proximity," "be within earshot," "be within sight," "be within range," and "be next to." These synonyms can be used interchangeably to convey a similar sense of being close or nearby.