simple past tense and past participle of compress
"The heavy machinery compressed the soil into a solid foundation before construction began."
In plain English: To compress something means to push it together so that it takes up less space than before.
"The file was compressed to save space on my hard drive."
flattened laterally along the whole length (e.g., certain leafstalks or flatfishes)
"The flatfish swims near the ocean floor with its body compressed laterally along its entire length."
Pressed tightly together.
"The old mattress was compressed so tightly that it barely had any give when I sat on it."