In medicine|lang=en terms the difference between serous and hydrops

is that serous is (medicine) containing, secreting, or resembling serum; watery; a fluid or discharge that is pale yellow and transparent, usually representing something of a benign nature (this contrasts with the term sanguine, which means blood-tinged and usually harmful) while hydrops is (medicine) the abnormal accumulation of serous fluid in a tissue or cavity.

As an adjective serous

is (medicine) containing, secreting, or resembling serum; watery; a fluid or discharge that is pale yellow and transparent, usually representing something of a benign nature (this contrasts with the term sanguine, which means blood-tinged and usually harmful).

As a noun hydrops is

(medicine) the abnormal accumulation of serous fluid in a tissue or cavity.

As nouns the difference between fluid and hydrops

is that fluid is any substance which can flow with relative ease, tends to assume the shape of its container, and obeys Bernoulli's principle; a liquid, gas or plasma while hydrops is the abnormal accumulation of serous fluid in a tissue or cavity.

As an adjective fluid

is of or relating to fluid.

As nouns the difference between tissue and hydrops

is that tissue is thin, woven, gauze-like fabric while hydrops is the abnormal accumulation of serous fluid in a tissue or cavity.

As a verb tissue

is to form tissue of; to interweave.

As nouns the difference between cavity and hydrops

is that cavity is a hole or hollow depression while hydrops is the abnormal accumulation of serous fluid in a tissue or cavity.

As nouns the difference between dropsy and hydrops

is that dropsy is swelling, edema, often from chronic obstructive pulmonary disease COPD while hydrops is the abnormal accumulation of serous fluid in a tissue or cavity.

As nouns the difference between sporange and megasporange

is that sporange is (dated) a sporangium while megasporange is a large sporange.

As an adjective rectangular

is having a shape like a rectangle.

As a noun megaron is

the rectangular great hall in a Mycenaean building, usually supported with pillars.

As nouns the difference between mycenaean and megaron

is that mycenaean is a native or inhabitant of Mycenae while megaron is the rectangular great hall in a Mycenaean building, usually supported with pillars.

As an adjective Mycenaean

is of or relating to ancient Mycenae or its inhabitants.

As a proper noun Mycenaean

is mycenaean Greek.

As nouns the difference between pillar and megaron

is that pillar is a large post, often used as supporting architecture while megaron is the rectangular great hall in a Mycenaean building, usually supported with pillars.

As a verb pillar

is to provide with pillars or added strength as if from pillars.

As nouns the difference between book and megaseller

is that book is a collection of sheets of paper bound together to hinge at one edge, containing printed or written material, pictures, etc while megaseller is a book or other product that has sold in extremely large numbers.

As a verb book

is to reserve (something) for future use.