PERIODICALNESS
Pe`ri*od"ic*al*ness, n.
Defn: Periodicity.
PERIODICITY
Pe`ri*o*dic"i*ty, n.; pl. Periodicities. Etym: [Cf. F. périodicité.]
Defn: The quality or state of being periodical, or regularly recurrent; as, the periodicity in the vital phenomena of plants. Henfrey.
PERIODIDE
Per*i"o*dide, n. Etym: [Pref. per- + iodide.]
Defn: An iodide containing a higher proportion of iodine than any other iodide of the same substance or series.
PERIODONTAL
Per`i*o*don"tal, a. Etym: [Pref. peri- + Gr. (Anat.)
Defn: Surrounding the teeth.
PERIODOSCOPE
Pe`ri*od"o*scope, n. Etym: [Period + -scope.] (Med.)
Defn: A table or other means for calculating the periodical functions of women. Dunglison.