|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.|
|hydrothermal (hī'drə-thûr'məl) Pronunciation Key
Relating to or produced by hot water, especially water heated underground by the Earth's internal heat. ◇ Hydrothermal energy is power that is generated using the Earth's hot water.