[医] 过, 高, 超, 经, 通; 极, 甚

Per- \Per-\ [See {Per}.]
1. A prefix used to signify through, throughout, by, for, or
as an intensive as perhaps, by hap or chance; perennial,
that lasts throughout the year; perforce, through or by
force; perfoliate, perforate; perspicuous, evident
throughout or very evident; perplex, literally, to
entangle very much.

2. (Chem.) Originally, denoting that the element to the name
of which it is prefixed in the respective compounds
exercised its highest valence; now, only that the element
has a higher valence than in other similar compounds;
thus, barium peroxide is the highest oxide of barium;
while nitrogen and manganese peroxides, so-called, are not
the highest oxides of those elements.