Trachytic is an adjective referring to a type of volcanic rock that is composed of small mineral grains and has a rough texture. Some synonyms that can be used for trachytic include porous, vesicular, and rough-textured. Other possible synonyms might include pumiceous, spongy, or frothy. These words help to convey the same general sense of a rock that is characterized by small air pockets and a rough surface, although they may differ in their specific connotations or nuances. Depending on the context in which it is used, different synonyms for trachytic may be more appropriate or effective at conveying the desired meaning.