As a proper noun precious

is .

As an adjective precarious is

(comparable) dangerously insecure or unstable; perilous or precarious can be (dentistry) relating to incipient caries.

As adjectives the difference between harmonic and enharmonic

is that harmonic is pertaining to harmony while enharmonic is describing two or more identical or almost identical notes that are written differently when in different keys. (Whether they are identical depends on the tuning method used..

As a noun harmonic

is a component frequency of the signal of a wave that is an integer multiple of the fundamental frequency.

As a verb delivered

is past tense of deliver.

As an adjective delivered

is that has been, or will be, delivered in a specific manner.

As a noun births is

plural of birth.

As nouns the difference between phlegm and cough

is that phlegm is (historical) one of the four humors making up the body in ancient and mediaeval medicine; said to be cold and moist, and often identified with mucus while cough is a sudden, usually noisy expulsion of air from the lungs, often involuntary.

As a verb cough is

to push air from the lungs in a quick, noisy explosion.

In mathematics terms the difference between quadratic and exponential

is that quadratic is a quadratic polynomial, function or equation while exponential is any function that has an exponent as an independent variable.

As nouns the difference between carbonara and alfredo

is that carbonara is a thick pasta sauce, usually made with eggs, cheese, and bacon while Alfredo is the sauce made from butter and Parmesan cheese used in dishes such as fettucine Alfredo, or any dish of this type.

As nouns the difference between rejection and failure

is that rejection is the act of rejecting while failure is state or condition of not meeting a desirable or intended objective, opposite of success.

As nouns the difference between irreconcilables and reservationists

is that irreconcilables is plural of irreconcilable while reservationists is plural of reservationist.

As nouns the difference between chairperson and secretary

is that chairperson is a chairman or chairwoman, someone who presides over a meeting, board, etc while secretary is someone entrusted with a secret; a confidant.

As a verb secretary is

to serve as a secretary of.

As nouns the difference between turgor and plasmolysis

is that turgor is the pressure produced by a solution in a space that is enclosed by a differentially permeable membrane while plasmolysis is the shrinking of protoplasm away from the cell wall of a plant or bacterium due to water loss.