Praise be to Allah, and peace and blessings be upon the Messenger of Allah.
Yes, “Al-Ahad” is one of the names of Allah that is explicitly mentioned in the Qur’an. Allah, the Exalted, says: ﴿Say: He is Allah, One. Allah, the Eternal Refuge.﴾ [Al-Ikhlas: 1–2]. Therefore, it is permissible to name a child “Abd al-Ahad,” just as it is permissible to name a child “Abd al-Samad.”
“Al-Ahad” means the One who has always been alone and with whom there has never been another.
He, Glorified and Exalted, is unique in His oneness in His Essence and attributes. He has no second, no partner, no equal, and no counterpart.
Some scholars have mentioned a distinction between the names “Al-Wahid” and “Al-Ahad.” It has been said that “Al-Wahid” indicates Allah’s uniqueness in His Essence, whereas “Al-Ahad” indicates His uniqueness in His Essence, meanings, and attributes.
It has also been said that “Al-Wahid” refers to the One who is unique in His Essence, without equal or counterpart, while “Al-Ahad” is based on the meaning of absolute uniqueness and is among the attributes with which Allah has uniquely described Himself.
Allah, Glorified and Exalted, is the One and the Unique, who has no partner or counterpart. He is the One toward whom the hearts of His servants turn, whom they seek in their needs, and upon whom they rely exclusively.
Allah says:
﴿And your God is One God. There is no deity except Him, the Most Compassionate, the Most Merciful.﴾
[Al-Baqarah: 163]
He is the One who has no equal, and everything besides Him, even if it may be described as one in some respect, is not one in every respect. As for Allah, He is uniquely characterized by absolute perfection.
Allah’s oneness means denying that He has any likenesses or equals. He, Glorified and Exalted, has no equal and no counterpart. He is the One God and the One Lord, and therefore no one besides Him truly deserves worship and obedience.
Allah says:
﴿Say: He is Allah, One.﴾
[Al-Ikhlas: 1]
Allah is unique in all attributes of perfection, and no one shares these attributes with Him. One implication of believing in this is that He must be singled out in belief, speech, and action. The servant believes in His absolute perfection and uniqueness and devotes every form of worship exclusively to Him.
Since “Al-Ahad” is one of the names of Allah, it is permissible to say “Abd al-Ahad”, just as it is permissible to say “Abd al-Samad.”
The meaning is that the servant is a servant of Allah, the One who is unique in His oneness and perfection, who has no partner or equal.
“Al-Ahad” is one of the names of Allah. The Qur’an explicitly mentions it in Surat Al-Ikhlas. It means the One who is unique in His oneness, who has no partner, equal, or counterpart, and who is unique in all attributes of perfection.
It is permissible to name a child “Abd al-Ahad” because it is connected to one of the names of Allah, just as it is permissible to name a child “Abd al-Samad.”
And Allah knows best.