(botany) a tube produced by a germinating spore, such as the pollen tube produced by a pollen grain
[gurnz-bak] /ˈgɜrnz bæk/ noun 1. Hugo, 1884–1967, U.S. publisher and inventor, born in Belgium: a pioneer in science-fiction publishing.
gero- or ger- pref. Old age: geroderma.
geroderma ger·o·der·ma (jěr’ō-dûr’mə) n. Thinning of the skin accompanied by the loss of elasticity and subcutaneous fat, as in the aging process.
[jer-uh-don-tiks, jeer-] /ˌdʒɛr əˈdɒn tɪks, ˌdʒɪər-/ noun, (used with a singular verb) 1. the branch of dentistry dealing with aging and aged persons. gerodontics ger·o·don·tics (jěr’ə-dŏn’tĭks) n. The branch of dentistry that deals with the diagnosis, prevention, and treatment of dental diseases and problems specific to old people.