bi-

¹bi-

prefix

Definition of BI-

1

a : two <bilateral> b : into two parts <bifurcate>

2

: twice : doubly : on both sides <biconvex>

3

: between, involving, or affecting two (specified) symmetrical parts <bilabial>

4

a : containing one (specified) constituent in double the proportion of the other constituent or in double the ordinary proportion <bicarbonate> b : di- <biphenyl>