protein

As a noun protein

is protein.

As a letter x is

the twenty-fourth letter of the.

As a symbol x is

voiceless velar fricative.

As nouns the difference between lab and protein

is that lab is (astronomy|galaxy) lyman-alpha blob while protein is protein.

As nouns the difference between bar and protein

is that bar is bar while protein is protein.

As nouns the difference between gain and protein

is that gain is the act of gaining or gain can be (architecture) a square or bevelled notch cut out of a girder, binding joist, or other timber which supports a floor beam, so as to receive the end of the floor beam while protein is protein.

As a preposition gain

is (obsolete) against.

As an adjective gain

is (obsolete) straight, direct; near; short.

As an adverb gain

is (obsolete) straightly; quickly; by the nearest way or means.

As a verb gain

is to acquire possession of what one did not have before.

As nouns the difference between initialism and protein

is that initialism is a term formed from the initial letter or letters of several words or parts of words, but which is itself pronounced letter by letter while protein is protein.

As a noun protein

is protein.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between protein and chitin

is that protein is protein while chitin is chitin.