The term 'plantlike animal' can be summarized by the crossword solution 'SPONGE, ' which is a six-letter word. Sponges are primitive aquatic animals that lack true tissues and organs, and they are classified as members of the phylum Porifera. Sponges are filter feeders, meaning they use specialized cells to filter food particles from the water. They are also sessile, meaning they are permanently attached to a surface and cannot move around. Sponges are considered plantlike animals because they are able to photosynthesize, meaning they can produce their own food using sunlight.