Verses with the word eunuch in the Old Testament (2 verses):

Isaiah 56:3
Neither let the son of the stranger, that hath joined himself to the LORD, speak, saying, The LORD hath utterly separated me from his people: neither let the eunuch say, Behold, I am a dry tree.

Jeremiah 52:25
He took also out of the city an eunuch, which had the charge of the men of war; and seven men of them that were near the king's person, which were found in the city; and the principal scribe of the host, who mustered the people of the land; and threescore men of the people of the land, that were found in the midst of the city.