p1 is a mora [linguistics]/component of syllable p2=s1 in language s2.
A syllable containing one mora is said to be monomoraic (=pavyslakypau); a syllable with two morae is said to be bimoraic (=relslakypau). Also, in rarer cases, a syllable with three morae is said to be trimoraic (=cibyslakypau).