Definition: The word "crossopterygian" refers to a type of fish that belongs to a group called "crossopterygii." Most of these fish are known only from fossils, which means we mostly see them in old remains rather than as live fish today.
In more advanced discussions, you might find "crossopterygian" used in paleontology or evolutionary biology when discussing the transition of life from water to land.
The word "crossopterygian" specifically refers to a group of fish and does not have multiple meanings in common usage. It is primarily used in scientific contexts.
There are no direct synonyms for "crossopterygian," but you might refer to them more generally as "ancient fish" or "fossil fish" when speaking broadly.
There are no common idioms or phrasal verbs associated with "crossopterygian," as it is a specific scientific term.
"Crossopterygian" is a specialized term used primarily in science to refer to a group of ancient fish known mainly from fossils.