Glossary H
Horizontal classification means a grouping of species from a similar time interval of evolution rather than those sharing a common lineage (horizontal with respect to a phylogenetic tree). Compare --->'vertical classification'.
A Handheld vacuum is a machine which is portable and sometimes cordless which make them ideal for cleaning small areas like the car. In addition to upright vacuums, it is good to use handheld vacuums because they can clean areas which an upright can not clean because they are too large.
The term handheld refers to any object that is designed to be light and small enough to be held and/or operated with one or both hands.
Harpsichord (in Italian cembalo; and in French clavecin) is defined as a stringed keyboard instrument in which the strings are plucked to produce sound.