The term "cutaneous" refers to the skin. Subcutaneous means beneath, or under, all the layers of the skin. For example, a subcutaneous cyst is under the skin.
Gawkrodger DJ, Ardern-Jones MR. Microanatomy of the skin. In: Gawkrodger DJ, Ardern-Jones MR, eds. Dermatology: An Illustrated Colour Text. 7th ed. Philadelphia, PA: Elsevier; 2021:chap 1.
Merriam-Webster's Medical Dictionary. Subcutaneous. www.merriam-webster.com/medical. Accessed October 22, 2020.