-aceous, -acea, -aceae, -aceaen, -aceus

(Latin: a suffix; having the quality of, of the nature of, characterized by, belonging to, resembling)

There are hunderds of words that utilize the -aceous suffix which are not shown here; however, the following will present important examples.

A suffix that forms adjectives and is used with technical combinations, especially in biological terms: "pertaining or belonging to, of the nature of, or characterized by; to be full of, to possess abundantly". The suffix -acea usually denotes "orders and classes in zoology" while the suffix -aceae usually denotes "orders and families in botany" and -aceaen is used to denote members of "orders of the animal kingdom".

capillaceous (adjective), more capillaceous, most capillaceous
1. Resembling a hair: There were a few capillaceous fibers on Jack's shirt which his wife removed before they went out to dine.
2. Regarding something that has many filaments that resemble a hair or thread: The fake für collar on Barbara's jacket was quite capillaceous and so very soft and smooth!
caprifoliaceous (adjective), more caprifoliaceous, most caprifoliaceous
1. Relating to, or belonging to the family Caprifoliaceae: Caprifoliaceous plants thrive in temperate and boreal regions and include shrubs or small trees like honeysuckle, elderberry, and the guelder rose.
2. Etymology: from New Latin caprifoliaceae, from caprifolium type genus, from Medieval Latin: "honeysuckle", from Latin caper, "goat" + folium, "leaf".
carbonaceous (adjective), more carbonaceous, most carbonaceous
Pertaining to, containing, or composed of, carbon; like coal: Lance's father was in a group of scientists who found a piece of carbonaceous asteroid and they were beyond being excited!

Teachers used to use paper impregnated with a carbonaceous substance to make copies of exercise sheets for their students.

carboraceous (adjective) (not comparable)
Regarding deposits with combustion residues: Such carboraceous matter include those containing lead or lead composites.
ceraceous (adjective), more ceraceous, most ceraceous
Pertaining to something that is waxen; like wax; ceracious: The pollen masses produced by orchids are ceraceous due to the texture and color of new wax.
Cetacea (proper noun)
A taxonomic order or marine mammals, including the whales, dolphins, and porpoises: The order of Cetacea comprises two extant suborders, the Odentoceta and the Mysticeta, including the whales, dolphins, and porpoises. The bodies of these mammals are streamlined, the forelimbs are modified as flippers, the hind-limbs are absent, and their tails bear lateral flukes. The nares are dorsal, the eyes are small, and the pinnae is absent. The skin is essentially hairless with a thick layer of subcutaneous fat for insulation. And, for breathing, they have a blow-hole on top of their heads.
cetacean (adjective), more cetacean, most cetacean (pl)
Any of various wholly aquatic placental mammals belonging to the order Cetacea, which includes the dolphins, porpoises, and whales. Their bodies are fish-shaped and adapted for swimming, with forelimbs in the form of paddlelike flippers. Functional hindlimbs are not seen. The long tail ends in two tranverse flukes, horizontally flattened tail used for locomotion. Hair is found only on the muzzle. There is a thick layer of fat (blubber) beneath the skin.
cetacean mammal (s) (noun), cetacean mammals (pl)
One of two families of large aquatic carnivorous mammals: Cetacean mammals have flipper-like forelimbs, no hind limbs, but paddle shaped tails. The Cetacean mammals include whales, dolphins, porpoises, and narwhals.
cetaceous (adjective) (not comparable)
Descriptive of any of a number of large marine organisms with long hairless bodies and fins: The whale is among the largest of the cetaceous mammals in the sea.
chloranthaceous (adjective) (not comparable)
Belonging to the plant-family Chloranthaceæ: There were a few chloranthaceous trees and bushes that were very fragrant in Mary's garden.
cineraceous (adjective), more cineraceous, most cineraceous
Relating to something ash-colored or like ashes; cinereous: After a long search Nancy finally found her ring in the cineraceous residue in the fireplace at home.
columbaceous (adjective) (not comparable)
Pertaining to a bird of the suborder Columbacei: The columbaceous birds called pigeons were lined up on top the neighbor's house and were cooing very loudly.
conchylaceous (adjective), more conchylaceous, most conchylaceous
Resembling, or of the nature of shells: Linda's necklace seemed to be of a conchylaceous quality, bearing the color and shapes of shells.
cretaceous (adjective) (not comparable)
Pertaining to chalk: The white sticks the children used for drawing or writing on the school's blackboard were of a cretaceous nature and produced quite a large amount of white residue when in use.
crustacean (s) (noun), crustaceans; crustacea (pl)
A member of the subphylum Crustacea: The crustaceans Mr. Smart talked about in biology class were the lobsters, shrimps, crabs, barnacles, and woodlice.

Also see this closely related -eous suffix unit.