H Very Common

a nonmetallic univalent element that is normally a colorless and odorless highly flammable diatomic gas; the simplest and lightest and most abundant element in the universe

a unit of inductance in which an induced electromotive force of one volt is produced when the current is varied at the rate of one ampere per second

the constant of proportionality relating the energy of a photon to its frequency; approximately 6.626 x 10^-34 joule-second

the 8th letter of the Roman alphabet

(thermodynamics) a thermodynamic quantity equal to the internal energy of a system plus the product of its volume and pressure

"enthalpy is the amount of energy in a system capable of doing mechanical work"

Abbreviation of hour (particularly when used as a (non-SI) unit of time alongside International System of Units (SI) units)

Abbreviation of hits.

Hentai.

Abbreviation of hard in reference to a grade of pencil lead.

Synonym of AH: in the year of the Hegira, used to mark dates employing the Islamic calendar.

The eighth letter of the English alphabet, called aitch and written in the Latin script.

The ordinal number eighth, derived from this letter of the English alphabet, called aitch and written in the Latin script.

Used as a filler response when one does not have a response to use. Almost always used by itself.