Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
rf is a noun meaning "a substance produced by the hypothalamus that is capable of accelerating the secretion of a given hormone by the anterior pituitary gland". It carries 3 recorded senses.
a substance produced by the hypothalamus that is capable of accelerating the secretion of a given hormone by the anterior pituitary gland
a radioactive transuranic element which has been synthesized
a complex neural network in the central core of the brainstem; monitors the state of the body and functions in such processes as arousal and sleep and attention and muscle tone
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for rf come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.