As a noun infinity

is (label) endlessness, unlimitedness, absence of end or limit.

As an adjective infinityfold is

(rare) by a multiple of infinity; by infinity times as much or as many.

As an adverb infinityfold is

(rare) by a factor of infinity.

As a noun factor

is (obsolete) a doer, maker; a person who does things for another person or organization.

As a verb factor

is to find all the factors of (a number or other mathematical object) (the objects that divide it evenly).

As an adjective infinityfold is

(rare) by a multiple of infinity; by infinity times as much or as many.

As an adverb infinityfold is

(rare) by a factor of infinity.

Infinityfold is a related term of fewfold.

As adjectives the difference between fewfold and infinityfold

is that fewfold is by a multiple of a few; by a few times as much or as many while infinityfold is by a multiple of infinity; by infinity times as much or as many.

As adverbs the difference between fewfold and infinityfold

is that fewfold is by a factor of a few while infinityfold is by a factor of infinity.

Severalfold is a related term of infinityfold.

As adjectives the difference between severalfold and infinityfold

is that severalfold is by several times while infinityfold is (rare) by a multiple of infinity; by infinity times as much or as many.

As adverbs the difference between severalfold and infinityfold

is that severalfold is by a factor of a several while infinityfold is (rare) by a factor of infinity.

Manyfold is a related term of infinityfold.

As adverbs the difference between manyfold and infinityfold

is that manyfold is by many times while infinityfold is (rare) by a factor of infinity.

As adjectives the difference between manyfold and infinityfold

is that manyfold is (dated) many while infinityfold is (rare) by a multiple of infinity; by infinity times as much or as many.

As adjectives the difference between multiple and fewfold

is that multiple is multiple while fewfold is by a multiple of a few; by a few times as much or as many.

As an adverb fewfold is

by a factor of a few.

As a proper noun few

is (british) the pilots who fought in the battle of britain.

As an adjective fewfold is

by a multiple of a few; by a few times as much or as many.

As an adverb fewfold is

by a factor of a few.

Exahertz is a related term of petahertz.

As nouns the difference between petahertz and exahertz

is that petahertz is {{SI-unit-np|peta|hertz|frequency} while exahertz is a unit of measurement based on one quintillion hertz.

Petahertz is a derived term of phz.

Phz is likely misspelled.

Phz has no English definition.

As a noun petahertz is

{{SI-unit-np|peta|hertz|frequency}.

As nouns the difference between hertz and yottahertz

is that hertz is in the International System of Units, the derived unit of frequency; one (period or cycle of any periodic event) per second. Symbol: Hz while yottahertz is a unit of measurement based on one septillion hertz.