Libramasculine is a gender in which one is mostly agender but experiences a small amount of attachment to being masculine/male. It's similar to demiboy, but is more specifically partially masculine and partially agender, with the agender part outweighing the masculine part, while demiboy is partially male, partially any other gender(s). Libramasculine people often identify as non-binary. If a libramasculine person is not assigned male at birth they might also consider themselves transmasculine.
The feminine equivalent is librafeminine, the non-binary equivalent is libranonbinary.