Merchant vessels can be referred to using a variety of synonyms. One such term is "freighters", which emphasizes the vessels' role in transporting goods. Another synonym is "cargo ships", which specifically refers to ships that carry cargo for commercial purposes. "Trade ships" is another commonly used term, as it highlights the connection between these vessels and commerce.
Additionally, some people may refer to merchant vessels as "merchantmen", which is an older term that has fallen out of common use. Other synonyms include "merchant ships", "merchant carriers", and "merchant boats".
Regardless of the specific term used, all of these synonyms refer to ships that are primarily engaged in commercial transport of goods and materials.