Perineuronal is a term that is used to describe a specific location or position in relation to a neuron or nerve cell. Synonyms for perineuronal might include words like surrounding, encircling, or enveloping, as these all convey the idea of something that is located closely around or adjacent to a neuron. Other possible synonyms for perineuronal might include terms like proximal, nearby, or contiguous, all of which suggest a close proximity or association with the neuron in question. Overall, different synonyms for perineuronal can help to convey slightly different meanings or nuances, depending on the context in which they are used.