With relation to cosmetics, a substance that is synthetic, not originating from nature.

Any substance that has a pleasant smell

Any substance that constrict or contracts the skin locally.  May be natural or synthetic.   

One of many forms of oleresins extracted from a variety of trees including benzoin from trees in central America containing benzoic acid or cinnamic acid. Used quite often in soaps, creams, lotions an [..]

Used primarily to neutralize the trace metals in water.  These trace metals can cause residue, oxidization, separation etc.  Many cosmetic companies will use a chelating agent as a cheap alternative t [..]

A natural protein substance vital to all skin and connective tissue.  As we age or with over-exposure to the sun, collagen production in the body is reduced leading to wrinkles, sagging skin and other [..]

Plugs of sebaceous oil and debris that obstruct pores and hair follicles appearing like white-heads or black-heads.  Product and ingredients that are listed as “comedogenic” are considered to be culpr [..]

The official FDA definition is "Articles intended to be rubbed, poured, sprinkled or sprayed, on introduced into, or somehow otherwise applied to the human body for the purpose of cleansing, [..]

Referring to or affecting the cutis (deeper layer of skin).