hyp·som·e·ter 
(hĭp-sŏmĭ-tər)
(hĭp-sŏmĭ-tər)n.
An instrument using the atmospheric pressure as measured by the change in the boiling point of water to determine land elevations.
- illness
- illness anxiety disorder
- illogic
- illogical
- illogicality
- illogically
- illogicalness
- ill-sorted
- ill-starred
- ill-tempered
- ill-temperedly
- ill-timed
- ill-treat
- ill-treatment
- illume
- illuminable
- illuminance
- illuminant
- illuminate
- illuminati
- illuminatingly
- illumination
- illuminative
- illuminator
- illumine