n.
Pronunciation: h ī - ' drä-tr ə - ˌ pi-z ə m
Function: noun
Etymology: International Scientific Vocabulary
Date: circa 1882
: a tropism (as in plant roots) in which water or water vapor is the orienting factor
– hy · dro · tro · pic \ ˌ h ī -dr ə - ' tr ō -pik, - ' trä- \ adjective