Semen is the Latin equivalent of 'seed'. It's a neuter gender noun in the singular. Its literal meaning is 'what is sown or planted, seed'; or 'what recently has grown from seed', such as a young shoot, seedling, scion, child. Its looser translation is 'race, stock'; 'elements' in the sense of water, stone, fire, etc.; 'cause, origin'; or 'author, instigator'.